The XXXI International Conference on Neutrino Physics and Astrophysics (Neutrino 2024) will be held in Milano, Italy, from June 16 to June 22.
The conference is jointly organized by University of Milano - Bicocca, University of Milano and INFN.
This biennial conference focuses on the current status of neutrino physics, its interplay with astronomy and cosmology, as well as the future prospects of these fields.
Chair: Takaaki Kajita
Moderator: C. Brofferio
Moderator: C. Brofferio
Introduction to the Conference
Moderator: T. Kajita
Abstract: This talk highlights the Borexino developments and discoveries, both from technical and scientific points of view, which can be useful for the experiments currently in preparation. From the technical point of view this experiment codified the methods for the scintillator purification and for the construction and installation of the detector which must be able to maintain the unprecedented levels of radiopurity obtained for the scintillator. From the scientific point of view, Borexino wrote a fundamental page for Sun and stars scientific knowledge, identifying the mechanisms that power them and therefore make them shine. In neutrino physics, Borexino was able to measure the electron-neutrino survival probability in a wide energy range from about 100 keV up to 15 MeV and it has been one of the two experiments that measured geo-neutrinos.
Moderator: T. Kajita
Title: Where are we and where are we going?
Moderator: T. Kajita
Chair: Serguey Petcov
T2K is a long-baseline neutrino oscillation experiment exploiting a beam of muon neutrinos or antineutrinos produced at the Japan Particle Accelerator Research Centre (J-PARC). Neutrinos are observed before oscillations at a Near Detector complex, located inside J-PARC at 280 m from the target, and at the far detector, Super-Kamiokande, 295 km away, where samples of electron and muon (anti-)neutrinos are selected.
In this talk we will show the latest T2K oscillation analyses results, including the results from the joint fit of the T2K beam samples with the atmospheric neutrinos from Super-Kamiokande.
In addition we will also describe the upgrades recently completed on the beamline, that allowed to reach the initial design beam power of 750 kW, and the upgrades of the off-axis Near Detector complex, consisting in the installation of a new high granularity target (Super-FGD), surrounded by two new High-Angle TPCs and six Time-Of-Flight planes.
T2K prospects for the next years of data taking will also be discussed in the talk.
NOvA is a two-detector accelerator neutrino oscillation experiment. Using Fermilab's newly Megawatt-capable NuMI neutrino beam, NOvA measures the disappearance of muon (anti)neutrinos and the appearance of electron (anti)neutrinos at the far detector, 810 km from the source. These oscillations are observed relative to the unoscillated beam composition measured at the functionally equivalent near detector, also located at Fermilab, which enables significant cancellation of systematic uncertainties. From these, we obtain precision measurements of the larger neutrino mass splitting and the largest neutrino mixing angle, as well as constraints on the octant of that angle, the neutrino mass ordering, and neutrino CP violation. In this talk I will present new measurements of these parameters using 10 years of NOvA data collected between 2013 and 2023, which includes twice the neutrino-mode exposure of our previous results.
Chair: Joachim Kopp
MicroBooNE’s beyond the standard model (BSM) physics program spans searches for feebly interacting dark sector particles, investigations of the MiniBooNE Low Energy Excess, and searches for light eV-scale sterile neutrinos. This program is carried out with data collected from Fermilab’s BNB and off-axis NuMI neutrino beams. With five years of data collected, MicroBooNE is sensitive to a broad range of new physics models. This talk will present recent results from MicroBooNE’s broad BSM physics program, and describe the novel analysis techniques which are enabling it.
The ICARUS collaboration employed the 760-ton T600 detector in a successful three-year physics run at the underground LNGS laboratory, performing a sensitive search for LSND-like anomalous e appearance in the CERN Neutrino to Gran Sasso beam, which contributed to the constraints on the allowed neutrino oscillation parameters to a narrow region around 1 eV 2 . After a significant overhaul at CERN, the T600 detector has been installed at Fermilab. In 2020 the cryogenic commissioning began with detector cool down, liquid argon filling and recirculation. ICARUS then started its operation collecting the first neutrino events from the Booster Neutrino Beam (BNB) and the Neutrinos at the Main Injector (NuMI) beam off-axis, which were used to test the ICARUS
event selection, reconstruction and analysis algorithms. ICARUS successfully completed its commissioning phase in June 2022, moving then to data taking for neutrino oscillation physics, aiming at first to either confirm or refute the claim by the Neutrino-4 short-baseline reactor experiment. ICARUS will also perform measurement of neutrino cross sections in LAr with the NuMI beam
and several Beyond Standard Model studies. After the first year of operations, ICARUS will search for evidence of sterile neutrinos jointly with the Short- Baseline Near Detector, within the Short-Baseline Neutrino program. In this presentation, preliminary results from the ICARUS data with the BNB and NuMI beams are presented, both in terms of performance of all ICARUS subsystems
and of capability to select and reconstruct neutrino events.
The study of neutrino properties and oscillations has entered the precision era, and control of systematic uncertainties in the present and next generation of accelerator-based experiments is required to maximize the sensitivity of their measurements. One of the leading uncertainties in many measurements and searches for physics beyond the Standard Model arises from the neutrino flux predominantly coming from hadron production. This talk will review the challenges and impact of neutrino flux predictions and their uncertainties in neutrino experiments, and discuss recent efforts and future prospects to measure hadron scattering and production of neutrino parents by the NA61/SHINE experiment at CERN and the EMPHATIC experiment at Fermilab.
Chair: Yifang Wang
A new generation of experiments have measured the IBD antineutrino spectrum generated by nuclear reactors in the last 12 years with unprecedented accuracy. With respect to the Huber-Mueller model, they have revealed a short-distance deficit, manifesting as an over-prediction at the top of the spectrum, as well as an underprediction at around 6 MeV - which has become colloquially known as ‘the bump’. Several possibilities have been put forward to explain these features, including faulty or incomplete modelling, and the possible existence of sterile neutrinos. In this presentation we will review (a) the latest results from nuclear reactor experiments, (b) normalization issues in the electron spectra measured at the Institut Laue Langevin in the 1980s, (c) impact of electron spectra measured to derive decay heat values, (d) recent upgrades to the summation method, on both the fission yields and decay data, and (e) future experiments to resolve outstanding issues.
The unveiling of the reactor antineutrino anomaly in 2011 revived interest in measurements at very short distances from reactors with primary motivation to test the hypothesis of an oscillation towards a sterile neutrino of mass around 1 eV as an explanation for the observed deficit of neutrinos compared with predictions. An experimental program has been developed at commercial as well as research reactors. In this presentation, I will discuss the challenges of these experiments, carried out at the earth's surface and with reduced target volumes. I will review the oscillation analyses that test the sterile neutrino hypothesis in a model-independent way. We will see that through this generation of experiments, the neutrino spectra emitted by the reactors are measured with great precision, providing a new benchmark for future neutrino experiments as well as for the nuclear data involved in predictions.
Chair: Mauro Mezzetto
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino oscillation experiment and underground neutrino observatory using liquid argon time projection chamber technology. DUNE will definitively resolve the neutrino mass ordering, and measure the mixing matrix parameters including the CP violating phase, with sensitivity to CP violation over a broad range of possible values. DUNE is also sensitive to MeV-scale neutrinos, with unique sensitivity to electron neutrinos from the neutronization burst of a supernova, and complementary to other experiments that are predominantly sensitive to electron antineutrinos. DUNE will search for a broad range of new physics signals, including direct detection as well as oscillation signatures beyond the three-flavor model. The excavation project of the far detector site at SURF was recently completed, and DUNE is on schedule for first physics results in this decade. The P5 report released in December in the United States strongly endorses the completion of DUNE with construction in two phases, together with critical international contributions and collaboration. This talk will cover the science and status of DUNE, including updated sensitivities with the most recent schedule, as well as results and progress from DUNE prototype detectors.
The Hyper-Kamiokande project (Hyper-K) comprises a large water Cherenkov detector, an order of magnitude larger than Super-Kamiokande, equipped with photosensors, electronics, and daq with higher capabilities, and a neutrino beam created with a MegaWatt-class beamline at the J-PARC accelerator complex. The main physics goals of Hyper-K are the discovery of CP violation in the lepton sector, precise measurements of neutrino oscillation parameters, observation of nucleon decay, and the study of neutrinos from astrophysical origins. Toward its commissioning in 2027, facility construction of the far detector, the Hyper-K detector, is progressing on time. Excavation of the dome part of the largest cavern, with a diameter of 69 m, and the design of the water tank and photosensor support structure have been completed. Preparation of Hyper-K detector components and near detectors including a new intermediate water Cherenkov detector (IWCD) is ongoing. This talk will cover the physics goals and the status of construction.
The violation of CP symmetry was discovered in the hadronic sector, proving that CP is not a conserved symmetry of nature. However, the amount of asymmetry observed is more than two orders of magnitude too small to explain the disappearance of antimatter. It is therefore essential to search for and measure CP violation in the leptonic sector in neutrino oscillation experiments, which has the potential to explain the observed density of matter in the universe. There are several models describing the matter-antimatter asymmetry in the universe, as well as models describing the origin of flavors, whose predictions together cover a wide range of δ CP values. It is therefore essential to measure δ CP with the highest possible precision in order to confirm or falsify these models.
The European Spallation Source neutrino Super Beam (ESSnuSB) project aims at maximizing the event statistics at the second neutrino oscillation maximum which thanks to the powerful 5 MW ESS proton linac will lead to an error in δ CP smaller than 8 degrees for all values of δ CP . ESSnuSB is a phased program using a low energy monitored neutrino beam and a low energy nuSTORM to measure the neutrino cross sections in the first phase ESSnuSB+ to be followed by the main program to measure CP violation in the second phase.
In this talk, a general overview of the ESSnuSB design study program will be presented, with emphasis on the current phase of the project. This project is supported by the EU through two design studies, ESSnuSB and ESSnuSB+.
Chair: Francesco Vissani
It is known that the lepton mixing angles are completely different from the quark mixing angles.
The fundamental principle behind the flavor mixing structure remains unknown. I shall review the different approaches to predict the lepton mixing angles and the Dirac and Majorana CP violation phases from theory, commenting also on their experimental tests. Their implications in neutrino oscillation, neutrinoless double decay and cosmology will be discussed.
Extensions of the Standard Model explaining neutrino masses and oscillations lead to a possible understanding of why the Universe contains more baryons than antibaryons. I will discuss how the baryogenesis and a mechanism of Majorana neutrino mass generation may be experimentally tested.
Chair: Giorgio Gratta
The LEGEND experimental program is dedicated to the search for the neutrinoless double-beta (0νββ) decay of 76Ge with isotopically-enriched high-purity germanium (HPGe) detectors and a discovery sensitivity beyond a half-life of 1028 years. The first phase of the project, LEGEND-200, is stably accumulating physics data at LNGS since more than one year with 140 kg of HPGe detectors, and plans to install more in the coming months. The Collaboration has scrutinized this first data to assess the sensitivity of the experiment and study the composition of the LEGEND-200 residual background. In this talk, we will present the performance of the experiment in terms of background rejection and signal acceptance, the current observed background in the region of interest, and a first model of the background composition before analysis cuts. We will conclude with an update on the status of the experiment's future phase, LEGEND-1000.
KamLAND-Zen is a double beta decay experiment that exploits the existing KamLAND neutrino detector which realizes an ultra-low background environment. The xenon-loaded liquid scintillator in a spherical nylon balloon was deployed at the center of the KamLAND detector. The first search for neutrinoless double-beta decay of 136Xe with 381 kg of xenon (KamLAND-Zen 400) demonstrated excellent sensitivity. To enhance the sensitivity, the KamLAND-Zen detector was upgraded to larger volume containing 745 kg xenon (KamLAND-Zen 800), corresponding to a twofold increase. In this talk, we will present the result of the improved search using complete KamLAND-Zen dataset, corresponding to an exposure of about 2 ton-yr of 136Xe. In the future, the KamLAND detector is planned to be upgraded to improve the search sensitivity (KamLAND2-Zen), and final optimizations of design are ongoing.
The CUORE (Cryogenic Underground Observatory for Rare Events) experiment is one of the most sensitive probes to date of the fundamental nature of neutrinos.
CUORE is located deep underground in the Laboratori Nazionali del Gran Sasso (LNGS) in Italy, allowing for a sensitive search for neutrinoless double beta decay (0νββ) and other rare processes.
CUORE searches for 0νββ in Te-130 and utilizes an array of cryogenic calorimeters made of TeO2 crystals, cooled down to below 15 mK.
CUORE has been continuously taking data since 2019, achieving a 90% uptime and having collected more than 2.5 ton yr of TeO2 exposure. This is the largest dataset ever collected by a high-resolution solid-state 0νββ experiment.
CUORE's capabilities extend beyond 0nuBB searches. In this talk, CUORE will present the most recent NLDBD results with a 2-ton-year dataset, one of the most precise measurements of the two-neutrino double beta decay half-lives and spectra and the complete reconstruction of backgrounds across a wide energy range. Moreover the future prospects will be discussed.
Chair: Erin O'Sullivan
The IceCube Neutrino Observatory is a neutrino telescope that the uses the glacial ice at the South Pole to capture high energy neutrinos, probing extreme phenomena in our Universe. In this talk I will present recent highlights from the collaboration, including our latest results characterizing the properties of the diffuse astrophysical flux, a multi-energy neutrino search in connection with the brightest ever gamma ray burst, and the first image of our galaxy in neutrinos. I will then discuss future prospects for advancing the field with IceCube-Gen2.
The KM3NeT neutrino telescope is currently under construction in the Mediterranean sea. The detector is built in a modular fashion, with individual detection units (DUs) being deployed and starting data taking immediately after. With two detector configurations, KM3NeT is both searching for astrophysical neutrino sources with the KM3NeT/ARCA detectors, and measuring neutrino properties via atmospheric neutrino oscillations with KM3NeT/ORCA. In this talk, I will present the latest results and status of the KM3NeT collaboration, focusing on the first 3 years of data taking.
$^{214}$Pb represents one of the most common irreducible contaminant in rare-events physics experiments.
In the XENONnT experiment, a LXe dual-phase TPC for direct dark matter searches, $^{214}$Pb represents the dominant contribution in the electron recoil background below 40 keV.
This isotope undergoes beta decay into several $^{214}$Bi excited states, generating electron/gamma events in the detector.
For several precision physics searches in XENONnT, such as solar-pp neutrino flux measurement, the accuracy demanded on this isotope branching ratios are still not currently available in the literature.
In this study, by exploiting $^{222}$Rn calibration campaign, we report updated measurements of $^{214}$Pb branching ratios.
The Deep Underground Neutrino Experiment (DUNE) is a next-generation neutrino experiment currently under construction. DUNE will consist of two high-resolution neutrino interaction imaging detectors exposed to the world’s most intense neutrino beam, with the Near Detector at Fermilab and the Far Detector 1,300 km away in the Sanford Underground Research Facility in South Dakota, US.
The high statistics and excellent resolution capabilities of DUNE's $^{40}$Ar detector will allow us to make precision studies of oscillation parameters capable of searching for CP violation in the lepton sector, testing interaction models, and studying phenomena that have, until now, seemed too complex to measure, like $\nu_\tau$ detection and therefore, providing the completion of the 3-flavor neutrino paradigm. Knowledge of the $\nu_\tau$ detection can impact a broad spectrum of open questions. These include searching for non-standard neutrino interactions, constraining the unitarity of the PMNS matrix, searching the sterile neutrinos, and studying neutrino interactions.
In the case of LArTPC data, the detector hits can be considered nodes in a graph, and the edges represent the spatial and temporal relationships between them. By using graph neural networks, it is possible to exploit these relationships and improve the accuracy of particle identification and reconstruction. During my presentation and specifically for tau neutrino reconstruction, I will show the effectiveness and reliability of our in-house developed graph neural network (GNN), NuGraph. This GNN classifies detector hits based on the particle type responsible for their production, assuring that the system accurately identifies and categorizes information based on its unique characteristics.
Liquid Argon Time Projection Chamber (LArTPC) is a premier technology in neutrino detector designs. The field response model describes the electric currents induced in the anode plane when ionization electrons drift in the chamber. Field response is critical for TPC readout simulation and charge reconstruction. A novel pixelated charge readout technology, LArPix, has been developed for LArTPCs. We present a new 3D field response simulation for these pixelated anode designs used in the Module-0 Demonstrator, which is operated as a prototype for the DUNE liquid argon near detector. In the prototype detector run, evidence of the readout triggered by drifting charge in advance of the charge arrival at the anode plane has been noticed. Thus, this field response simulation is also crucial in understanding electronics response and optimizing pixel pad geometry to reduce the induced signal trigger effect.
Neutrino emission can be expected from Gamma Ray Bursts (GRBs) through hadronic interactions, though the exact neutrino flux may vary depending on the GRB environment. To test the neutrino emission at different energies in different environments and improve the description of low-energy or thermal contributions, we created a model calculating the neutrino yield from GRB internal energy dissipations. We assume a proton spectrum consisting of a thermal distribution combined with a non-thermal power law proton distribution. These protons interact between themselves as well as with photon spectrum, modelled as a Band function, to create pions. The pion and muon decays as well as the photon-proton interactions have been simulated using the newly released AM3 software to calculate the expected neutrino flux. The obtained result includes sub-TeV neutrinos from the thermal proton population. The flux at Earth is obtained for different parameters to demonstrate the possibilities of probing various GRB populations with the current and next generation of neutrino telescopes.
In the next ten years, neutrino telescopes will become increasingly sensitive to galactic neutrinos, the flux of neutrinos produced by astrophysical sources and in cosmic ray interactions within our galaxy. This new flux offers a promising laboratory for exploring beyond the standard model neutrino physics dependent on ultra-long baselines. However, searches for these BSM signals will require improved understanding of the galactic neutrino distribution, since the signal will depend on the spread of neutrino production at different distances along a given galactic line of sight. This additional dimension has not been used in galactic neutrino searches and has not been modeled. We use the cosmic ray propagation software CRPropa to produce a four-dimensional spatial and energy neutrino distribution by simulating the collisions between galactic cosmic rays and gas. We vary the input gas maps, cosmic ray source distributions and spectra, magnetic field properties, and interaction cross-sections and calculate their effect on the resulting neutrino distribution. We also compare our four-dimensional distributions to existing galactic neutrino maps. By understanding where neutrinos are produced within our galaxy, we hope to enable new tests of neutrino properties and interactions.
DUNE is a leading-edge experiment for neutrino oscillation physics and is
currently under construction in the United States, between Fermilab, where
neutrino beam is generated, and the SURF underground laboratory, in South
Dakota, hosting the Far Detector at a depth of 4,850 mwe and at a baseline
of nearly 1,300 km. GRAIN (GRanular Argon for Interactions of Neutrinos) is
the Liquid Argon detector of SAND (System for On-Axis Neutrino Detection),
which is part of the DUNE Near Detector complex. SAND is expected to
significantly decrease uncertainties related to neutrino flux and cross-sections.
Additionally, SAND will have the capacity to monitor the beam stability, and to
investigate various neutrino interactions models, constraining at the same time
nuclear effects. A key element of SAND is GRAIN, which will serve as a Liquid
Argon target for detecting neutrinos and low-energy particles, ensuring crosscalibration
with the other Near Detector components. This poster will discuss
the novel GRAIN system designed for reconstructing charged particle tracks in
LAr. It is based on the detection of scintillation light by an optical system
optimised for the Vacuum Ultra-Violet, coupled to SiPM matrices. Another
research topic that will be described concerns the development of a cryogenic,
1024-channel ASIC, able to read 32x32 SiPM matrices.
The TAMBO experiment aims to investigate the tau neutrino component within the astrophysical neutrino flux. One of our ongoing endeavors involves identifying the optimal data acquisition system (DAQ) to be used in conjunction with the synchronization system. The synchronization system plays a crucial role in identifying the air shower initiated by the tau lepton as it exits the rock.
In this context, we present two distinct DAQ prototypes. The first DAQ prototype utilizes an FPGA for high-accuracy digital processing and 4-frequency beacon wireless detection for synchronization purposes. Conversely, the second DAQ prototype is based on Red Pitaya and employs a wired synchronization system utilizing a GPS-disciplined clock.
We will implement an experimental setup comprising three scintillator planes to evaluate the wired synchronization system's performance. Each plane will be positioned at the vertex of an equilateral triangle with sides measuring ~ 80 -100 meters.
Demonstrating a highly efficient single ion barium tagging sensor could reduce backgrounds in searches for neutrinoless double beta decay ($0\nu\beta\beta$) to negligible levels in ton to multi-ton scale experiments. The NEXT collaboration is pursuing a phased program aimed at searching for $0\nu\beta\beta$ utilizing high-pressure xenon gas time projection chambers (TPC) with the introduction of a future barium tagging phase using single molecule fluorescence imaging (SMFI). In the following, I will present recent advances in the development of single ion barium tagging technology based on SMFI using a novel high-pressure gas microscope and organic fluorophores for dry functionality, along with demonstration of single ion capture and imaging in a high-pressure xenon gas environment. This single-ion imaging microscope is a prototype sensor for future integration into a barium tagging high-pressure xenon gas TPC experiment. Lastly, outline the framework of a novel qubit-inspired ion sensor designed to integrate the sensing and transportation of the daughter ion produced in $0\nu\beta\beta$. This sensor will be realized through the utilization of advanced nanofabrication techniques, enabling the development of a photonic integrated chip. This framework aims to create a compact ion detector that is highly selective, dependable and adaptable for integration into a barium tagging TPC design.
IceCube-Gen2 is a planned extension of the IceCube Neutrino Observatory at the geographic South Pole. The array is optimized to search for sources of astrophysical neutrinos from TeV to EeV energies. IceCube-Gen2 builds on more than a decade of successful scientific observations with IceCube. The observatory will utilize optical sensor modules integrated into the deep ultra-clear Antarctic ice for the detection of Cherenkov light from neutrino interactions, surface detectors on the ice for the detection of cosmic-ray air showers, and an extended radio array for sensing of ultra-high-energy neutrinos. This presentation will review the array. Technologies for the construction and operations of the Gen2 detector will be described, with a particular emphasis on sustainability, environmental impact, and resource optimization.
The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator detector located 700 m underground at 52.5 km from two Nuclear Power Plants (NPP) in China. The primary physics goal of JUNO is to determine the neutrino mass ordering by measuring the electron antineutrino ($\bar{\nu}_e$) oscillated spectrum with excellent energy resolution. This requires a very accurate knowledge of the non-oscillated reactor $\bar{\nu}_e$ spectrum. The Taishan Antineutrino Observatory (TAO) is a satellite experiment consisting of a ton-level liquid scintillator detector that will measure the $\bar{\nu}_e$ spectrum with unprecedented energy resolution at 44 m from the core of a reactor at the Taishan NPP, providing a reference spectrum for JUNO.
This poster presents the analysis tools that we are developing to simulate the evolution of the reactor $\bar{\nu}_e$ spectrum as a function of fuel burnup and to implement a $\bar{\nu}_e$ summation spectrum, based on most up-to-date nuclear data, to be used for future benchmark analyses of TAO data.
The IceCube Observatory is a cubic-kilometer neutrino telescope built into the deep glacial ice at the South Pole. The IceCube Upgrade is the future low-energy extension to the existing detector array, characterized by denser instrumentation and improved detection units. This setup will allow us to study neutrino oscillations with greater sensitivity compared to the existing instrumentation, improve neutrino mass ordering studies, and test for the PMNS mixing matrix unitarity with high precision. The reconstruction of event information, in particular the direction of an incoming neutrino, is a crucial ingredient to all of the oscillation analyses. In this poster, we present the approximate resolution limits in directional reconstruction for cascade-like events in IceCube Upgrade and discuss the factors that limit the reconstruction performance. The reconstruction limits are compared with the performances of the state-of-the-art reconstruction algorithms of IceCube.
T2K is a long-baseline accelerator neutrino experiment that has delivered world-leading measurements of the atmospheric mixing angle and the magnitude of CP-violation in neutrino oscillations. Here we show that Bayesian analyses using the PDG parameters benefit certain flavour symmetries through their choice of uniform prior, and we consider alternate parameterisations that exhaust choices of symmetry. We conclude that T2K’s Bayesian framework MaCh3 produces constraints that are largely invariant under these priors. The usual parameters already yield the most conservative constraint for the amount of CP-violation but the octant of $\theta_{23}$ is still dependent on the flavour structure we choose for our prior.
The IceCube Neutrino Observatory is sensitive from 0.5 GeV to the PeV energy range for astrophysical neutrino searches. In addition, the supernova Data Acquisition System (DAQ) allows the collaboration to be sensitive to close-by core-collapse supernovae at MeV energies. There exists, however, a gap between these covered energy ranges. This poster presents ongoing efforts to cover this gap. We will discuss various strategies to reach this goal through the use of HitSpool, a specific DAQ within IceCube, and the construction of a new event selection based on machine learning and citizen science.
LEGEND-1000 is a next-generation ton-scale experiment searching for neutrinoless double beta decay of $^{76}$Ge using p-type, high-purity germanium detectors. The experiment is planned for 1000 kg of Ge detectors enriched to more than 90$\%$ in $^{76}$Ge.
The experiment is going to be installed at LNGS (3800 mwe) to reduce direct and induced backgrounds from cosmic rays.
While standard analysis techniques are very effective in removing prompt backgrounds, muon-induced events, associated with the production of long-lived isotopes in Ge detectors, require the application of delayed coincidence cuts between muon veto, liquid argon veto and the Ge detectors.
We present the design principles for the new active veto for LEGEND-1000 at LNGS. The goal is to instrument the atmospheric liquid argon volume and enhance the delayed coincidence cut efficiency by identifying neutron captures in argon via de-excitation gammas. We will discuss the various readout options considered and their performance, estimated through Geant4 simulations.
This work is supported by the U.S. DOE and the NSF, the LANL, ORNL and LBNL LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Russian RFBR; the Canadian NSERC and CFI; the LNGS, SNOLAB, and SURF facilities.
Large-scale 6Li-doped pulse shape sensitive plastic scintillator is one of several technologies under development within the Mobile Antineutrino Demonstrator project. Liquid scintillator with similar capabilities was one of key aspects of the aboveground reactor antineutrino detection demonstration by the PROSPECT experiment. However, a plastic material is considered a requirement for truly mobile above-ground detection systems suited to reactor monitoring for safeguards. The new formulation of plastic scintillator is being developed in partnership with Eljen Technologies and can be obtained in multi-liter single volumes enabling the construction of segments at meter-scale lengths. We will present a summary of measured performance criteria, which include attenuation length, stability, pulse shape sensitivity, and neutron efficiency measurements.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-861441
The Cryogenic Underground Observatory for Rare Events (CUORE) is a tonne scale detector designed to search for neutrinoless double beta decay ($0\nu\beta\beta$) in $^{130}$Te. The CUORE detector is made of 988 TeO$_{2}$ crystals operated at around 15 mK in the Gran Sasso National Laboratory(Italy).
The unfolding of the experimental backgrounds is of primary importance in discovering a very rare process like the $0\nu\beta\beta$ decay. Material screenings and assays, together with a detailed set of Monte Carlo simulations, accomplish this complex task, modeling the CUORE data. Moreover, the characterization of the experimental setup provides an essential input for the background budget of the next-generation experiment, CUPID, which will exploit the same cryogenic facility.
We will show the reconstruction of the 1 ton$\cdot$yr CUORE data by means of a simultaneous Bayesian fit of 39 different energy spectra over the entire detector energy range. The determination of the background components activities will be discussed, along with a comprehensive analysis of the fit systematics, which allows studying the space and time dependence of the contaminants.
We will also show a dedicated fit to the CUORE data for the precise determination of half-life and shape of the $2\nu\beta\beta$ decay of $^{130}$Te.
The observation of neutrinoless double beta (0ν2β) decay would give information on lepton number violation, as well as on the neutrino mass and nature (Dirac or Majorana particle). The CROSS project (Cryogenic Rare event Observatory with Surface Sensitivity) uses bolometers with embedded with Mo100 and Te130 isotopes, which are susceptible to decay through this hypothetical process. The CROSS bolometers are installed in a dedicated cryogenic facility in the Canfranc underground laboratory, Spain. As the main challenge of an experiment aimed to detect 0ν2β decay is to reduce the background contribution in the region of interest (ROI), the CROSS experiment is developing bolometers capable to discriminate the background from surface alpha and beta interactions. Moreover, to tag and eliminate muon-related events, the experimental setup includes a heavy passive shielding and an active muon veto system made of plastic scintillators. Background modeling is essential in experiments searching for rare processes. For that purpose, a new MonteCarlo simulation of the CROSS experiment has been designed using the GEANT4 toolkit. This simulation has lead to calculate several background contributions in the ROI. Furthermore, it has allowed to develop targeted strategies to reduce background by applying event selections based on energy depositions observed across different detectors.
Next generation neutrinoless double beta experiments aims at covering the inverted hierarchy region of the neutrino mass spectrum, with sensitivities on the half-lives greater than 10$^{27}$ years. The CUPID experiment will exploit cryogenic calorimeters to search for neutrinoless double beta decay of $^{100}$Mo. To reach the target sensitivities one of the key requirements is the understanding and control of the backgrounds. The poster will detail the background sources relevant to the CUPID experiment. We will show the estimation of the background index for each of the sources, based on background models of past experiments and from detector performances in R&D tests.
NOvA is a long baseline neutrino oscillation experiment, using Fermilab's NuMI beam and a functionally identical near and far detector. NOvA measures muon neutrino disappearance and electron neutrino appearance to probe neutrino oscillation parameters, including the large neutrino mixing angle, the mass ordering, and the CP-violating phase. NOvA has developed a Bayesian analysis in addition to its Frequentist analysis, using Markov Chain Monte Carlo. This Bayesian framework allows for measurements previously difficult to make with the Frequentist framework, such as the Jarlskog invariant and the reactor mixing angle. The details and status of the Bayesian Framework will be presented, as well as latest NOvA results on measurements of three-flavor oscillation parameters.
The domain of low energy neutrinos is at the edge of making important measurements, among which the Diffuse Supernova Neutrino Background and the Upturn of the electron flavor survival probability of solar neutrinos. In this context, the next generation of Cherenkov detectors will need algorithms that outperform traditional regression algorithms to reconstruct both low and high energy charged particle events. Key challengers for this task are Neural Networks, as they have become increasingly more performant and reliable during the last decade, and their use for physics regression and classification tasks have proved their worth regarding the possible gain of precision, accuracy and computation time.
This work will present the current status of a machine learning (ML) model based on Graph Neural Networks aiming at predicting relevant variables of low energy charged particle events in Cherenkov detectors, such as the vertex of interaction and the particle's energy. In particular, a Bayesian Neural Network based on stochastic variational inference is considered. The advantages of this type of Neural Network will be presented, most notably its ability to probe the uncertainties of the model's weight and biases, which is an important improvement over other ML models. The performance of our model will then be showed using Monte-Carlo simulations of future Cherenkov detectors such as Hyper-Kamiokande (HK), Water Cherenkov Test Experiment (WCTE) and Intermediate Water Cherenkov Detector (IWCD).
BINGO is a project dedicated to explore and demonstrate new methods for background reduction in cryogenic calorimetric $0\nu\beta\beta$ searches. With a target background index at the level of $10^{-5}$ counts/(keV kg yr) it aims at providing a path towards a nearly background free $0\nu\beta\beta$ experiment with a tonne of the isotopes of interest $^{100}$Mo and $^{130}$Te. The major design aspects to achieve this goal are (i) a novel detector assembly reducing the exposed surface area of un-instrumented (passive) materials in the detector array by more than an order of magnitude, (ii) an additional tightly packed array of BGO scintillators that surrounds the detector array and acts as active cryogenic veto system and (iii) the use of enhanced Neganov-Trofimov-Luke based light detectors that help mitigate the pile-up background for $^{100}$Mo and ensure the alpha-beta discrimination in $^{130}$TeO$_2$. In this poster we will describe the technical design of these concepts, results from prototypes of the technologies in proof-of concept measurements and initial Geant4 based projections of the impact of these improvements in a CUORE/CUPID size experiment.
Experiments searching for neutrinoless double beta decay (0νββ) are pushing the boundaries of technology to achieve sensitivities to half-lives on the order of 10$^{28}$ years or beyond. A promising approach involves detecting the daughter barium ion generated in the double beta decay of $^{136}$Xe. The NEXT collaboration is investigating chemical sensors to identify the Ba$^{2+}$ coinciding with the emission of two electrons. This entails a challenge, since only a few signal-candidate ions per year would be produced in the NEXT chamber. Further the chemosensors must be compatible with the ultra-dry conditions of xenon gas.
The NEXT group working in Barium tagging is exploring different families of molecular indicators which produce different types of fluorescence signals upon binding to Ba$^{2+}$. First: on-off molecules, with high yield when forming a complex with Ba$^{2+}$. Second: bi-color molecules, with spectral emission shift when they interact with the ion. Third: time-resolved molecules with different decay lifetimes. Different surface-science techniques are being developed to characterise each molecular family and will be detailed in this contribution. Furthermore, a custom-engineered, finely-tuned Ba$^{2+}$ beam is being developed to reproduce the conditions in the final NEXT detector of high pressure xenon. The response of the fluorescent molecules after exposure to this beam will assure the viability of such a barium tagging sensor.
The Deep Underground Neutrino Experiment, DUNE, is a next-generation, long-baseline, neutrino experiment, and flagship project for the U.S. It is poised to perform some of the most precise measurements of the properties of neutrinos in order to elucidate their role in the outstanding matter-antimatter asymmetry. DUNE will make use of the most intense neutrino beams produced by the Fermi National Accelerator Lab in Batavia, Illinois and propagate them towards a far detector located 800 miles away and a mile underground at the Sanford Underground Research facility (SURF) in Lead, South Dakota. At a nominal 70 kilotons of liquid Argon, the DUNE far detector will be the largest Liquid Argon Time Projection Chamber (LArTPC)-based neutrino observatory in the world. The level of precision required to answer the questions sought after by DUNE, result in unprecedented requirements in our understanding of the detector response. We must therefore, carefully address various systematic uncertainties, particularly those in position and energy reconstruction of neutrino interactions and their byproducts. I will talk about the challenges involved in calibrating the largest LArTPC ever to be built and elaborate on the sophisticated calibration systems, catered for DUNE, to provide the precision required to achieve future breakthrough discoveries.
We investigate the possibility of using the Short Baseline Near Detector at Fermilab, with and without employing the PRISM concept, to constrain the pion and kaon leptonic flavor (and number) violating decays. We show that we can put stringent limits on the flavor violating branching ratios.
The upgrade of the T2K near detector, ND280, will improve the physics capabilities of the experiment, including a reduced proton momentum threshold, increased angular acceptance, and the ability to reconstruct neutron kinematics on an event by event basis. Central to the near detector upgrade is the Super Fine Grained Detector (SuperFGD), which consists of approximately two million optically isolated 1 cm scintillator cubes.
The SuperFGD has been assembled and installed at J-PARC, commissioned using LED, cosmic and T2K neutrino beam data, and is now taking physics data in the T2K neutrino beam. This poster presents the efforts in commissioning the detector and characterisation of the detector response, which is critical for making use of data in physics analyses. Plans for the first analyses are also presented.
Observation of high-energy neutrinos from the direction of nearby active galaxy, NGC 1068, was a major step in identifying for the origin of high-energy neutrinos. This observation revealed that high-energy neutrinos originated at the heart of active galaxies which are opaque to gamma-ray emission. The realization that is reinforced by the excess of neutrinos in the direction of NGC 4151, another nearby AGN. Modeling neutrino emission from the core of AGN relies on the multi-wavelength observation of the inner parts of the active galaxy and is challenging due to the uncertainties associated with the absorption of emission in these dense environments. Here, we employ the measured neutrino spectra together with the sub-GeV $\gamma$-ray emission measured by the Fermi satellite to break the degeneracy and narrow in on the parameter space of neutrino emission from the coronae of AGN. Our result will help estimating the prospects for identification of additional sources and guide future targeted analyses
The Super Fine-Grained Detector (SFGD) is part of a significant upgrade to the near detector in the Tokai to Kamioka (T2K) long-baseline neutrino experiment. It serves to provide excellent precision in measurements of neutrino cross-sections, mass ordering and Charge-Parity asymmetry. With almost 2 million plastic scintillator cubes threaded with wavelength shifting fibres to make up about 56,000 channels, the commissioning and calibration of this detector presents numerous challenges.
This poster describes the calibration process and preparations for neutrino data taking with the SFGD, including the incorporation of the task management software Luigi, developed by the music streaming service Spotify. By automating the process, data taken with LED pulses between neutrino beam spills is used to monitor the stability of the high gain and other properties of the channel readout. The procedures for calculating the gain and pedestal, and classification of channel output are described, where results using LED data taken in February 2024 indicate good calibration for nearly all channels even at this early stage. With the full detector installation in April 2024, commissioning efforts will be finalised, reconstruction of particle tracks and identification can be re-calibrated, and physics analyses will commence.
T2K (Tokai to Kamioka) is a long baseline neutrino experiment located in Japan\cite{t2k}. Over the last few years, the experiment has been focused on the study of the $\delta_{CP}$ phase parameter of the PMNS matrix, which may introduce a Charge-Parity violation component in the Leptonic Sector. \
T2K has entered its Second Phase, characterized by upgrades of the Beam Line and of the Near Detector. The new Near Detector design includes the installation of a new target and tracking system, including two High Angle Time Projection Chambers devoted to the identification of charged particles at large angles with respect to beam direction\cite{t2kup}.\
HA-TPCs are based on a gaseous active volume contained in a Field Cage made of lightweight composite material, combining optimal mechanical and electrical properties with minimal radiation length and dead volume.
The readout is performed by innovative Resistive Micromegas modules featuring a resistive layer for charge spreading on top of the readout plane to enhance spatial resolution performances. The mentioned technologies have been tested during several test beams and cosmic rays campaigns\cite{cern2018}\cite{desy2019}\cite{cern2022}\cite{eram2023}. After the installation at J-Parc in Fall 2023, a commissioning period of data taking with cosmics and then with a neutrino beam has been performed.
This poster focuses on the characterization and commissioning performances of the HA-TPCs at CERN and J-Parc, including also the first results using beam neutrinos interactions.
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Abe, K.; et al. The T2K experiment. {\em Nucl. Instrum. Meth. A} {\bf 2011}, {\em 659}, 106--135.
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Abe, K.; et al. T2K ND280 Upgrade--Technical Design Report. {\em arXiv} {\bf 2019}, arXiv:1901.03750.
\bibitem[3]{cern2018}
Attié, D.; et al. Performances of a resistive Micromegas module for the Time Projection Chambers of the T2K Near Detector upgrade. {\em Nucl. Instrum. Meth. A} {\bf 2020}, {\em 957}, 163286.
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Attié, D.; et al. Characterization of resistive Micromegas detectors for the upgrade of the T2K Near Detector Time Projection Chambers. {\em Nucl. Instrum. Meth. A} {\bf 2022}, {\em 1025}, 166109.
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Attié, D.; et al. Analysis of test beam data taken with a prototype of TPC with resistive Micromegas for the T2K Near Detector upgrade. {\em Nucl. Instrum. Meth. A} {\bf 2023}, {\em 1052}, 168248.
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Ambrosi, L.; et al. Characterization of charge spreading and gain of encapsulated resistive Micromegas detectors for the upgrade of the T2K Near Detector Time Projection Chambers.{\em Nucl. Instrum. Meth. A} {\bf 2023} {\em 1056}, 168534.
\end{thebibliography}
In the search for neutrinoless double beta decay (0νββ) experiments, common data analysis methods include the traditional counting method within a region of interest, while energy spectrum fitting methods are used in some experiments like KamLAND-Zen. These two types of methods differ in their sensitivities to the 0νββ half-life.
Simulations are performed to quantify such differences, using the background conditions at the China Jinping Underground Laboratory (CJPL). The results of the simulation indicate that the fitting method would yield a higher sensitivity than the counting method by a factor of 1.25. This study discusses the source of these differences, and the conclusions can provide benefits for future 0νββ experiments in selecting data processing methods.
We derive the complete set of one-loop renormalization-group equations (RGEs) for the operators up to dimension-six (dim-6) in the seesaw effective field theories (SEFTs). Two kinds of contributions to those RGEs are identified, one from double insertions of the dimension-five (dim-5) Weinberg operator and the other from single insertions of the tree-level dim-6 operators in the SEFTs. A number of new results are presented. First, as the dim-5 Weinberg operator is unique in the standard model effective field theory (SMEFT), its contributions to the RGEs for the SEFTs are equally applicable to the SMEFT. We find the full contributions from the Weinberg operator to one-loop RGEs in the SMEFT, correcting the results existing in previous works, and confirm that those from dim-6 operators are consistent with the results in the literature. Second, in the type-I SEFT, we give the explicit expressions of the RGEs of all the physical parameters involved in the charged- and neutralcurrent interactions of leptons. Third, the RGEs are numerically solved to illustrate the running behaviors of the non-unitary parameters, mixing angles and CP-violating phases in the non-unitary leptonic flavor mixing matrix. Together with the one-loop matching results of the dim-5 and dim-6 operators and their Wilson coefficients, the present work has established a self-consistent framework up to dim-6 to investigate low-energy phenomena of three types of seesaw models at the one-loop level.
With detectors at both Fermilab and Ash River, Minnesota, in the United States, NOvA was built to investigate the intricate properties of neutrinos, with a principal emphasis on active three-flavour neutrino mixing phenomena. Comprising two functionally identical detectors, with the Near Detector located 1 km below ground at Fermilab and the Far Detector, located 810 km away and 14 mrad off the beam axis in Northern Minnesota, NOvA capitalizes on the expansive distance to scrutinize neutrino behaviour.
NOvA not only probes active neutrino mixing but also explores exotic oscillations, including sterile neutrinos. Uncertainties on the neutrino flux, cross-section, and detector systematics significantly contribute, complicating the disentanglement of genuine physics events from background noise. In this poster, we show the impact of systematic reduction via neutral current samples and its implications on oscillation parameters, leveraging results primarily from Monte Carlo simulations. We aim to enhance the precision of neutrino research and illuminate pathways towards a deeper comprehension of particle physics phenomena.
The Short Baseline Neutrino program at Fermilab aims to explore significant regions of parameter space, applicable to sterile neutrinos at the eV mass scale, as suggested by existing experimental anomalies. To this purpose it exploits Liquid Argon Time Projection Chamber detectors located along the Booster Neutrino Beamline to measure both νe appearance and νµ disappearance: the Short Baseline Neutrino Detector and the ICARUS-T600 detector at 110 and 600 m from the neutrino source, respectively. The ICARUS T-600 Far Detector, located at shallow depth, is surrounded by a Cosmic Ray Tagger system to mitigate the cosmic ray background. On average ~ 11 muon tracks are expected to cross the detector during the ~ 1 ms drift time. The cosmic ray tagger is composed of plastic scintillator bars, ensuring near 4π coverage of the detector aiming at tagging cosmic muons and thus reject 𝛾s produced by muon interactions in the surrounding materials that can generate an electromagnetic showers mimicking a νe signal. The system allows one to disentangle cosmic rays from particles originated in a neutrino interaction inside the detector by measuring their position and crossing time. A synchronization of the cosmic ray tagger with the ICARUS photon detection system with a nanosecond accuracy allows one to reject cosmic particles recorded during the beam spill and thus select an enriched sample of neutrino triggered events ahead of the event reconstruction. An overview of the cosmic ray tagger system as well as its role in the neutrino events identification and cosmic background rejection will be presented.
Xenon dual-phase time projections chambers (TPCs) have proven to be a successful technology in studying physical phenomena that require low-background conditions. With 40t of liquid xenon (LXe) in the TPC baseline design, DARWIN will have a high sensitivity for the detection of particle dark matter, neutrinoless double beta decay, and axion-like particles (ALPs). Although cosmic muons are a source of background that cannot be entirely eliminated, they may be greatly diminished by placing the detector deep underground. We used Monte Carlo simulations to model the cosmogenic background expected for the DARWIN observatory at several underground laboratories to determine the production rate of Xe-137, the most crucial isotope in the search for of the neutrinoless double beta decay of Xe-136.
We study the conditions under which the Majorana phase of the two flavor neutrino mixing matrix appears in the oscillation probabilities and causes $CP$ violation. We find that the Majorana phase remains in the neutrino evolution equation if the neutrino decay eigenstates are not aligned with the mass eigenstates. We show that, in general, two kinds of $CP$ violation are possible: one due to the Majorana phase and the other due to the phase of the off-diagonal element of the neutrino decay matrix. We find that the $CP$ violating terms in the oscillation probabilities are also sensitive to neutrino mass ordering.
The CUORE (Cryogenic Underground Observatory for Rare Events) experiment at Gran Sasso National Laboratory in Italy primarily searches for neutrinoless double-beta (0$\nu\beta\beta$) decay of $^{130}$Te. The CUORE detector consists of a close-packed array of 988 TeO$_2$ calorimetric detectors cooled to below 15 mK using a custom-built cryogen-free dilution refrigerator. The experiment is the first to demonstrate stable operation of a tonne-scale milli-kelvin cryogenic calorimeter. We present the analysis framework used for the latest CUORE data release corresponding to over 2 tonne$\cdot$year TeO$_2$ exposure. We focus on the improved signal processing and response modelling methods relative to our previous analysis, and the extraction of the 0$\nu\beta\beta$ decay result with a comprehensive overview of our coherent Bayesian approach.
The MicroBooNE detector, an 85-tonne active mass liquid argon time projection chamber (LArTPC) at Fermilab, is ideally suited to search for physics beyond the standard model due to its excellent calorimetric, spatial, and energy resolution. This poster will present several recent results using data recorded with Fermilab’s NuMI neutrino beam: a first search for dark-trident scattering in a neutrino beam, world-leading limits on heavy neutral lepton production, including the first limits on neutrino-neutral pion final states, and new constraints on Higgs portal scalar models.
Currently, the ICARUS-T600 liquid argon TPC is collecting data exposed to Booster Neutrino and Numi off-axis beams within the SBN program at Fermilab. A light detection system, based on PMTs deployed behind the TPC wire chambers, is in place to detect vacuum ultraviolet photons produced by ionizing particles in LAr. This system is fundamental for the detector operation, providing an efficient trigger and contributing to the 3D reconstruction of events. Moreover, since the TPC is exposed to a huge flux of cosmic rays due to its operations at shallow depths, the light detection system allows for the time reconstruction of events, contributing to the identification and to the selection of neutrino interactions within the beam spill gates.
This contribution will primarily focus on the comparative study (data vs. MC) of light signal of cosmic muons to validate the light emulation. An overview of the current analysis status and its first results will be reported.
MicroBooNE is a short-baseline neutrino oscillation experiment that employs a Liquid Argon Time Projection Chamber (LArTPC) together with an array of Photomultiplier Tubes (PMTs) which detect scintillation light. This light detection provides a means to reject cosmic ray backgrounds and trigger on beam-related interactions. Thus, accurate modeling of the expected optical detector signal is critical. MicroBooNE has been performing several measurements of scintillation light yield in order to perform detector calibrations as well as improve LAr scintillation light modeling more broadly. This poster will present the status of these measurements and how they are being used to inform updates to the detector light yield simulation in a data-driven way.
The Daya Bay Reactor Neutrino Experiment was designed with the primary goal of precisely measuring the neutrino mixing parameter, $\theta_{13}$. Eight identically-designed liquid scintillator detectors installed in three underground experimental halls measure the reactor antineutrinos from six nuclear reactors with different distances. In addition to the precise measurement via neutron capture on gadolinium, another independent measurement with distinct systematics could be carried out based on neutron capture by hydrogen. In this poster, the latest neutrino oscillation analysis results based on the 1958-day data with neutron capture by hydrogen will be presented. Moreover, the improved statistics and systematic control will be emphasized.
The ICARUS T600 detector is a liquid argon time projection chamber (LArTPC) installed at Fermilab, aimed towards a sensitive search for possible electron neutrino excess in the 200-600 MeV region. To investigate electron neutrino appearance signals in ICARUS, a fast and accurate algorithm for selecting electron neutrino events from a background of cosmic interactions is required. We present an application of the general-purpose deep learning based reconstruction algorithm developed at SLAC to the task of electron neutrino reconstruction in the ICARUS detector. We demonstrate its effectiveness using the ICARUS detector simulation dataset containing electron neutrino events and out-of-time cosmic interactions generated using the CORSIKA software. In addition, we compare the selection efficiency/purity and reconstructed energy resolution across different initial neutrino energy ranges, and discuss current efforts to improve reconstruction of low energy neutrino events.
DUNE is the flagship of the next generation of neutrino experiments in the United States. It is designed to decisively measure neutrino CP violation and the mass hierarchy. It utilizes the Liquid Argon Time Projection Chamber (LArTPC) technology, which provides exceptional spatial resolution and the potential to accurately identify final state particles and neutrino events. DUNE's high resolution LArTPC increases the difficulty of reconstructing and identifying neutrino events at DUNE. Deep learning techniques offer a promising solution to this problem. At DUNE, convolutional neural networks, graph neural networks and transformers are being developed and have already shown promising results in kinematic reconstruction, clustering and event/particle identification. Deep learning methods have also been preliminarily tested on data from the DUNE prototype detector ProtoDUNE at CERN. I will discuss the aforementioned progress on deep learning reconstruction at DUNE.
The IceCube Neutrino Observatory at the South Pole has sensitivity to all three active neutrino flavors created by atmospheric and astrophysical sources, spanning six orders of magnitude in energy. Using ten years of data and convolutional neural networks to identify astrophysical tau neutrino morphologies, we detected seven tau neutrino candidates on an estimated background of approximately 0.5 events, dominated by other astrophysical neutrino flavors. The estimated average energy of the candidate tau neutrinos is approximately 200 TeV. This is the first high-significance measurement of astrophysical tau neutrinos, and the most energetic tau neutrino candidates ever observed.
The NOvA experiment presents new measurements of the neutrino oscillation parameters obtained through a fit to data from the one megawatt NuMI neutrino beam in the NOvA detectors. The analysis uses muon-neutrino disappearance and electron-neutrino appearance in both neutrino and antineutrino beam polarities. With the addition of $\sim100\%$ more neutrino-mode beam exposure over the previously reported results, this analysis employs the unified approach of Feldman and Cousins to determine the confidence level intervals for the oscillation parameters $\theta_{23}$, $\delta_{\text{CP}}$, and $\Delta m_{32}^{2}$, for both neutrino mass orderings.
The Deep Underground Neutrino Experiment (DUNE) is a next-generation neutrino experiment that will consist of a near detector (ND) complex placed at Fermilab, several hundred meters downstream of the neutrino production point, and a larger far detector (FD) to be built in the Sanford Underground Research Facility (SURF), approximately 1300 km away. DUNE will record neutrino interactions from an accelerator-produced beam (the LBNF multi-megawatt wide-band neutrino beam planned for Fermilab) arriving at predictable times, but will also aim to detect rare events such as supernova neutrinos, potential nucleon decays and other beyond the Standard Model phenomena. The main role of the DUNE ND is constraining the systematic uncertainties in the neutrino oscillation measurements by characterising the energy spectrum and composition of the neutrino beam, as well as performing precision measurements of neutrino cross sections. The plan for DUNE is to be built using a staged approach with two main phases. While the Phase I ND complex is sufficient for early physics goals, a Phase II upgrade is planned in order to reach the designed sensitivity for the neutrino oscillation physics. The upgraded Phase II ND will feature ND-GAr, a magnetised high-pressure gaseous argon TPC surrounded by an electromagnetic calorimeter (ECal) and a muon tagger. The gaseous argon provides low detection thresholds, which would allow detailed measurements of nuclear effects at the interaction vertex using the same material as the FD. Additionally, the magnetic field and the ECal would enable efficient particle identification (PID) and momentum and charge reconstruction. GArSoft is the simulation and reconstruction software package developed for ND-GAr. The development of this software is crucial for the task of delivering a physics-driven detector design, as it allows us to understand the impact that design changes have on the physics. This poster will present an overview of the ND-GAr concept, the ongoing efforts on the simulation and reconstruction software and the PID capabilities of the detector.
The next-generation experiment CUPID (Cuore Upgrade with Particle IDentification) will search for $^{100}$Mo neutrinoless double beta decay (0ν2β) using enriched Li$_2$$^{100}$MoO$_4$ scintillating bolometers facing thin Ge cryogenic light detectors. The dual heat-light readout allows for the discrimination of the α-particles, an important background source in CUORE, CUPID’s predecessor, and improves the experimental sensitivity. In addition, the Ge light detectors will be equipped with Al electrodes to amplify their signal-to-noise ratio through the so-called Neganov-Trofimov-Luke (NTL) effect. The NTL technology will be the key to reject the pileup of $^{100}$Mo two neutrino double beta decay (2ν2β), a significant background to the 0ν2β search due to the relatively fast 2ν2β decay rate of 100Mo. Currently, various developments are pursued within the collaboration to obtain the best performance from these NTL light detectors and a reliable production process. In this poster, we will present the R&D efforts with the most recent obtained results, the future objectives, and how they will help to reject pileup to keep the background level within the designed level.
The discovery of neutrinoless double beta decay ($0\nu\beta\beta$) would be a huge step in the understanding of the nature of the neutrino. SuperNEMO is an experiment designed to search for $0\nu\beta\beta$, whose demonstrator module is located in Modane Underground Laboratory in France (4800 m.w.e). It uses a unique technique combining a tracker and a segmented, scintillator-based calorimeter that allows us to unambiguously identify the two final-state electrons and measure their arrival time and energy.
The calorimeter consists of so-called optical modules (OMs) composed of polystyrene scintillator coupled to photomultiplier tube (PMT). In order to achieve high detector sensitivity, precise energy calibration of individual OMs is necessary. A specialised calibration system consisting of 42 $^{207}$Bi calibration sources has been built for this purpose. These sources can be deployed on precise positions in the middle of the detector using 6 stepper motors. OMs are then calibrated using Auger electrons emitted through internal conversion of $^{207}$Bi.
There are different effects affecting energy measurement which have to be taken into account. First of all, electrons lose energy while travelling from the calibration source to an OM. Because of that, measured energy is different than the initial one. These losses can be estimated and corrected using model based on Bethe-Bloch formula. Besides these energy losses, the OMs themselves add some imperfections to the energy measurement. Their response is slightly non-linear because of Birks' law and Cherenkov radiation. The collection of scintillation light is also affected by the position of its emission. A correction describing these effects has been developed based on Monte-Carlo simulations.
Including the corrections into the calibration process is not a straightforward task. It leads to a problem of function minimisation which requires numerical solution. The details of this numerical approach will be presented.
Many current and future accelerator neutrino oscillation experiments, such as DUNE, rely on liquid argon time projection chamber (LArTPC) as the primary detection technology, benefiting from the high light yield from the liquid argon scintillation. However, propagating the scintillation light from the production to the readout channels is typically computationally challenging. A common solution is to use a look-up table to represent the process. Detectors are increasing in size and number of readout channels, but the need to maintain O(10 cm) granularity for the look-up tables remains constant, leading to billions of parameters being required. Therefore, the look-up table approach is not very scalable. We propose to use SIREN, an implicit neural representation with periodic activation functions, to model photon propagation. It can reproduce the look-up table in 3D with high precision using orders of magnitude fewer parameters. In addition, using the differentiable nature of the SIREN model, we can optimize the photon propagation model directly with data.
In recent years, the multi-messenger approach in Astrophysics has become a real game changer for better understanding the still unclear phenomena in our universe.
Neutrino telescopes can play a key role by highlighting the hadronic component of such phenomena, testing the known γ-ray sources.
In this contribution, we report the combined analyses of the data collected by two neutrino telescopes located at abyssal sites in the Mediterranean Sea. The ANTARES detector operated for more than 15 years off the coast of Toulon (France). KM3NeT/ARCA is one of two detectors of the next-generation KM3NeT observatory. It is optimized for astrophysical neutrinos of energy > 1 TeV and is currently collecting data, although still under construction off Portopalo di Capo Passero (Italy)..
The candidate list of about one hundred point-like and extended sources is tested for the neutrino emission. This list includes bright γ-ray emitters, galactic γ-ray sources with hints of a hadronic component (TeVCat), extragalactic AGN with high intensity flux observed in radio (VLBI), and the most significant candidate sources investigated by IceCube.
The data samples of the two experiments have also been combined in the search for a diffuse emission of cosmic neutrinos.
The Diffuse Supernova Neutrino Background (DSNB) is a theoretical astrophysical prediction of a collection of neutrinos from all core-collapse supernovae that ever existed in the Universe. It is yet to be observed. This presentation will showcase the latest results from the gadolinium-loaded Super-Kamiokande (SK) experiment and how it excludes certain theoretical models. While SK is primarily sensitive to the integrated value of the DSNB flux, the future Hyper-Kamiokande (HK) experiment will probe the shape of the spectrum in more detail. A study of HK sensitivity to relevant parameters, such as the fraction of black hole forming supernovae, will then be presented. Finally, the discussion will delve into how the observation of a nearby supernova could better constrain the DSNB models by measuring the supernova neutrino emission spectrum.
LArTPCs are the technology of choice for many current and future neutrino experiments. Improving the performance of LArTPCs to signals with energies less than 10 MeV would substantially enhance the flagship analyses of experiments like DUNE, while potentially enabling the physics of solar neutrinos, dark matter searches, and neutrinoless double beta decay searches.
I outline the pathway and progress on R&D for photosensitive dopants, whose introduction into the LAr active medium, has a potential to enable the detection of low-energy signals in large LArTPCs. This R&D program will demonstrate the feasibility and impacts of introducing doped LAr into current and future neutrino detectors at the kTon scale. I explain the impact of this technology on physics signals across energy ranges. I also show results from ongoing tests of this technology in the TinyTPC test-stand at Fermilab.
The Deep Underground Neutrino Experiment (DUNE), a pioneering project underway in the US, involves the construction of a next-generation neutrino experiment. This experiment features a broadband neutrino beam spanning from Fermilab to the Sanford Underground Research Facility (SURF) in Lead, South Dakota, incorporating a high-precision near detector and a substantial liquid argon time-projection chamber (LArTPC) far detector, represented by two prototypes – Proto-DUNE single-phase horizontal-drift (ProtoDUNE-HD) and ProtoDUNE single-phase vertical-drift (ProtoDUNE-VD). This study focuses on the DUNE's ability to reconstruct tau neutrino events in the far detector using the NUML graph neural network, essential for differentiating charged current muon, tau, and electron events and classifying hits by particle type.
The findings indicate that leveraging the simultaneous readout of an entire far detector module improves the Positive Prediction Value (PPV) and the True Negative Rate (TNR) compared to utilising individual readout modules in isolation, which would only sample portions of a neutrino interaction’s image
The Deep Underground Neutrino Experiment (DUNE) is a next generation experiment designed to measure the neutrino and anti-neutrino oscillation probabilities, using a high-intensity neutrino beam (1.2-2.4 MW) produced at Fermilab. With a baseline of 1300 km and large (kton-scale) LArTPC detectors, DUNE will provide an unprecedented precision in measuring the oscillation parameters. Neutrinos interaction cross sections represent the main source of systematics which enters the analysis and limits the sensitivity of measuring the CP violating phase and other oscillation parameters . The Precision Reaction Independent Spectrum Measurement (PRISM) represents an innovative technique for neutrino oscillation analysis, which has the potential to significantly reduce the interaction model dependency. The DUNE Near Detector (ND) complex is designed to move to different positions along the neutrino beam axis, sampling thus several neutrino fluxes with different peak energies as a function of the off-axis position. The PRISM concept linearly combines these off-axis neutrino measurements to produce data-driven predictions of the oscillated neutrino spectrum at the Far Detector (FD). An oscillated FD prediction obtained directly from data has a minimum modeling dependency, any cross section effects being naturally incorporated in the analysis. This poster will give an overview of the PRISM concept and how it is used within DUNE. A case-study showing how PRISM can avoid potential biases resulting from the wrong interaction modeling will also be presented.
In this work we have investigated neutrino oscillation in the presence of gravity, in particular the contorsion, which is the non-dynamical part of spin connection. The contraction of contorion field with tetrad gives us torsional coupling constants which can be probed by future long-baseline neutrino experiments like DUNE and P2SO. We use the notations $\lambda_{21}^{\prime}$ and $\lambda_{31}^{\prime}$ to define the torsional couplings in this study. We scrutinize the effect of new torsional couplings on neutrino oscillation probability; appearance and disappearance channel. It turns out that, appearance (disappearance) channel gets more affected by $\lambda_{21}^{\prime}$ ($\lambda_{31}^{\prime})$ when we take one coupling at a time. This feature encourages us to place bounds on the two torsional couplings $\lambda_{21}^{\prime}$ and $\lambda_{31}^{\prime}$ from P2SO and DUNE. The outcome shows that P2SO provides more parameter constraints than DUNE. Furthermore, we have demonstrated the shift in the sensitivities of mass ordering, octant of the atmospheric mixing angle $\theta_{23}$, and CP violation when the new couplings are present. The outcome indicates that changing $\lambda_{(2,3)1}^{\prime}$ from zero to non-zero value significantly alters each sector of physics sensitivity.
The Deep Underground Neutrino Experiment (DUNE) will advance the field of neutrino oscillation to the precision era, independently measuring the entire set of oscillation parameters, thanks to Liquid-Argon TPC technology. The Photon Detection System (PDS) will expand the scientific program of the experiment by providing triggers for non-beam events (atmospheric, solar, and supernova neutrinos) and enhancing the capabilities of the TPC for the long-baseline program.
The PDS of the first FD module consists of light collector modules placed in the inactive space between the innermost wire planes of the TPC anode. The light collectors, the so-called X-ARAPUCAs, are functionally light traps that capture wavelength-shifted photons inside boxes with highly reflective internal surfaces and a wavelength shifting bar to direct the photons onto a SiPM array. We show their functionality and how we assess their performance in standalone facilities (CIEMAT) and ProtoDUNE-HD (CERN).
The ProtoDUNE experiment is a full engineering prototype of the DUNE far detector, and took test beam data at CERN. ProtoDUNE-SP is the largest Liquid Argon Time Projection Chamber (LArTPC), which contains about 770 tons of liquid argon, with 420 tons in the active volume. The beam of the tertiary particles was designed to cover the expected spectrum of particles from neutrino interactions in the DUNE detectors. A key aspect of understanding these interactions is the accurate energy reconstruction of electron showers. This work focuses on improving the energy reconstruction for electron showers in the ProtoDUNE-SP detector. We apply an electron lifetime correction and a simulation-based evaluation of missing energy to improve our energy measurements. We study the correlation between reconstructed shower energy and beam momentum, as well as the resolution of the beam momentum itself. A relationship between the energy resolution of electron showers and beam momentum was studied. Our ongoing work involves developing the analysis for two ProtoDUNE technologies, i.e. horizontal(ProtoDUNE-HD) and vertical(ProtoDUNE-VD) drifts TPCs. Comparing the performance of energy reconstruction between these two detectors will provide valuable insights. This analysis contributes to improvements in understanding energy reconstruction techniques in the ProtoDUNE experiment, paving the way for more accurate neutrino interaction measurements.
The current and next generation of long-baseline neutrino experiments are bringing about the era of precision neutrino oscillation measurements. New detectors, technologies and analysis techniques are being developed to meet the challenges posed by these precision measurements. Water Cherenkov neutrino experiments have played a crucial role in neutrino discoveries over the years, providing a well-established and affordable way to instrument large target masses, and the future water-based detectors of Hyper-Kamiokande, ESSnuSB and THEIA are expected to observe unprecedented rates of neutrino interactions. A corresponding suppression of backgrounds and systematic uncertainties to the 1% level is required to achieve the goals of these experiments.
The Water Cherenkov Test Experiment (WCTE) is a 50-ton water Cherenkov detector that is scheduled to take data in 2024. The WCTE detector will receive tagged 200 MeV to 1 GeV electrons, muons, charged pions and protons from the CERN East Area T9 beam, as well as observing secondary neutrons and operating in a dedicated tagged photon setup. WCTE will be used to study the water Cherenkov detector response using new photosensor technologies, instrumented with multi-PMT modules each containing 19 3-inch PMTs. This provides a unique opportunity for new technologies and techniques to be demonstrated with known particle fluxes, towards reaching 1% level systematic uncertainties for GeV scale neutrino interactions. Advances in calibration, event reconstruction and analysis will be used in measurements including Cherenkov light production, lepton and pion scattering and secondary neutron production, which will also provide direct inputs to existing and future water Chernkov experiments.
This poster will provide an overview of the physics goals of WCTE, the novel analyses that will be used and demonstrated by each of these measurements, and how they will facilitate the goals of next generation neutrino experiments.
In core-collapse supernovae and neutron star mergers, the neutrino density is so large that neutrino-neutrino refraction can lead to collective flavor conversions independent of vacuum mixing. These are called fast flavor conversions since the neutrino self-interaction strength $\mu$ represents the characteristic time scale of the system. In the limit of vanishing vacuum mixing, one necessary condition for these conversions is the existence of a zero-crossing in the momentum angular distribution of neutrino FLN (Flavor Lepton Number). However, it has been empirically realized that the vacuum frequency $\omega$ can significantly affect the onset of flavor conversion even if $\mu \gg \omega$. In this work, we study more deeply the impact of $\omega$ on angular-driven flavor instabilities. Focusing on a homogeneous and axially symmetric neutrino gas, we show that a non-zero vacuum frequency is responsible for inducing flavor instabilities with a non-negligible growth rate in a neutrino gas that would be stable for $\omega=0$, despite the presence of a FLN angular zero-crossing. Relying on a perturbative approach, we establish a connection between odd powers of $\omega$ and the neutrino FPN (Flavor Particle Number) angular distribution, showing that flavor conversion dynamics under $\omega \neq 0$ are influenced by both FLN and FPN. We also explore the possibility of mapping the system with $\omega\neq0$ to an effective one with $\omega=0$.
The ANTARES neutrino telescope stopped gathering data in February 2022,
after nearly 16 years of operation. The detector consisted of 12 vertical lines forming a 3D array of photo-sensors, which instrumented about 10 megatons of Mediterranean seawater. We present a method using Deep Learning that improves the direction reconstruction of single-line events, for which the reconstruction of the azimuth angle of the incoming neutrino is particularly difficult. We are able to improve by a factor of two the resolution of the zenithal angle with respect to previous standard reconstruction techniques, and we give a first estimation of the azimuthal angle, which was previously missing.
We complete this direction reconstruction with an event classifier and an energy estimator for single-line events, developed using novel combinations of different machine learning techniques. To estimate the energy of the neutrino candidate, a Principal Component Analysis (PCA) is applied to the activations of pre-trained direction neural networks. These new components are used as inputs for a new network. The event classifier is trained applying Transfer Learning, since the first layers are the convolutional part of the direction networks. This implementation has shown better results than training from scratch. We are able to differentiate neutrinos inducing a muon (with a long track) from that inducing a cascade shower with an overall accuracy of around 80% and a precision of 84% for tracks and 77% for showers.
The improvements are highly relevant for low-energy neutrino studies. Point source multimessenger searches have been tested using these new techniques, allowing to extend the sensitivities to low neutrino energies. They are also being applied to a dark matter search towards the direction of the Sun, where a better sensitivitity compared to published analyses is expected for WIMP candidates with mass below 150 GeV.
The precise measurement of neutrino properties is a top priority in fundamental particle physics. Accelerator-based neutrino experiments provide a unique framework for such studies, offering oscillation measurements and insights into CP violation in the leptonic sector. The next-generations experiments aim to establish mass ordering and possibly discover charge-parity violation with 5σ significance, as well as measure the CP-parameterizing phase (δCP) with unprecedented precision.
The successor to Super-Kamiokande (SK), Hyper-Kamiokande (HK), is a next-generation Water Cherenkov detector with an eightfold increase in target volume, enhanced photodetector capacity, and precise calibration devices. To fully leverage HK's capabilities, we need to develop reliable and precise analysis tools. In this effort, the Water Cherenkov Test Experiment (WCTE) has been specifically designed to provide accurate measurements that help understand detector responses and test the performance of event-reconstruction algorithms.
This poster introduces GRANT, a graph neural network-based software for particle reconstruction in Hyper-Kamiokande. We first discuss its adaptation for WCTE, emphasizing the upcoming data-taking phase in autumn as an opportunity to validate our algorithm under real conditions. We will then present the initial and promising results, demonstrating GRANT’s potential to enhance HK's physics capabilities in the CP violation discovery range at the GeV scale.
The Cryogenic Underground Observatory for Rare Events (CUORE) experiment, located at the Gran Sasso National Laboratory in Italy, is an ongoing search for neutrinoless double beta decay. Previous work has shown that the quality of CUORE data can be enhanced through noise decorrelation algorithms utilizing auxiliary devices such as microphones, accelerometers, and seismometers. Here, I will showcase the application of these algorithms in improving CUORE's data quality, including enhancing detector baseline resolution, thus enabling lower thresholds and improved coincidence tagging. Additionally, I will outline the anticipated benefits of noise decorrelation on ongoing and future CUORE datasets, leveraging an expanded array of auxiliary devices including antennas and additional accelerometers.
Equity, Diversity, and Inclusion (EDI) are important to drive innovation in many different fields, including particle physics. Underground labs are working on many different fronts to improve EDI in their host countries and within particle physics collaborations. Laboratories can institute policies to protect their staff and make improvements to their facilities to increase accessibility. Laboratories can encourage the scientific collaborations they host to have policies and plans for increasing EDI. SNOLAB is supporting employees and user-bases in different ways. Some examples are targeted outreach, consultation with experimental collaborations on their own policies, EDI training, and Indigenous cultural recognition. These efforts are intended to enhance the equity and inclusion of their communities.
Recent discoveries made by neutrino telescopes such as the IceCube Neutrino Observatory relied extensively on machine learning tools to infer physical quantities from the raw photon hits detected. Reconstruction algorithms are limited by the sparse sampling of photons by the optical modules due to the relatively large spacing (10 − 100 m) between them in the detector. In this paper, we propose a novel technique for enhancing the amount of information available to any reconstruction algorithm through the use of deep learning-driven super-resolution of data events. Our strategy embeds additional “virtual” optical modules within the existing physical detector geometry and
trains a convolutional neural network to predict the hits on these virtual optical modules. We show that this technique improves the angular reconstruction of low-energy track and cascade events in a generic ice-based neutrino telescope, though our results readily extend to water-based neutrino telescopes.
The Photon Detection System (PDS) of the first two DUNE far detectors, FD1 and FD2, is
composed of large area photon detection units named X-Arapuca; they embed large area PMMA based wavelength shifting lightguides and dichroic filters custom developed and produced for the LAr environment.
The PDS will complement and boost the calorimetry of the LArTPC, enable the detection of non beam events such as supernova neutrino bursts, and improve the vertex reconstruction of the beam.
The X-Arapuca is a photon trap with two down-shifting stages, driving photons to SiPMs where they are eventually collected. It is an assembly of several components, whose grade and coupling determines its Photon Detection Efficiency (PDE), and consequently the PDS sensitivity of the DUNE physics reach.
An experimental study is presented showing how specific changes to the baseline components of both the FD1 and the FD2 X-Arapuca enhances its PDE, hence the DUNE PDS sensitivity. The impact of each of the X-Arapuca main components is quantified.
New characterization at cryogenic temperatures of the absorbance, photo-luminescence and light emission time profile of the VUV sensitive fluors (pTP, BBT) will be presented: they are at the basis of the LAr Photon Detection Systems for DUNE and can be employed in low background LAr experiments.
The features and the radiocontaminant budget of the large area PMMA based down-shifting lightguides are presented and discussed. These lightguides can be directly coated with VUV sensitive fluors employing dip-coating and wire bar coating techniques.
These technologies are also relevant for the DUNE FD3 and low background experiments, such as LEGEND-1000, where WLS lightguides of similar shape and size are being considered.
Hybrid neutrino detectors utilize both Cherenkov and scintillation light, combining the lower energy threshold of pure scintillators with the enhanced direction resolution of water. These detectors offer improved performance capabilities for fundamental physics goals as well as applications such as nuclear nonproliferation. Benchtop-scale experiments have shown success in Cherenkov/scintillation separation. A tons-scale test is needed to extrapolate the performance to future large hybrid detectors like Theia, with a fiducial volume of tens of kT. Eos is a 20-ton detector with an approximately 4-ton fiducial volume under construction at UC Berkeley and Lawrence Berkeley National Laboratory. Featuring fast photomultiplier tubes (900 ps transit time spread), a novel water-based liquid scintillator (WbLS) target, and a first large-scale test of spectral sorting, Eos will be a test-bed for emerging technologies. Eos will deploy calibration sources to verify the optical models of WbLS and other liquid scintillators with slow light emission, and to support development of advanced techniques for reconstructing event energy, position, and direction in hybrid detectors. This will prove vital when extrapolating to the kT-scale. After achieving these goals, Eos can be moved near a nuclear reactor or into a particle test-beam to demonstrate neutrino event reconstruction or detailed event characterization with these novel detection technologies.
The ICARUS T600 LArTPC detector was refurbished after an initial run at
the underground LNGS labs and is currently taking data within its experimental hall at Fermilab after full commissioning. Regular data taking began in May 2021 with neutrinos from the Booster Neutrino Beam (BNB) and the Neutrinos at the Main Injector (NuMI) off-axis beam. As the far detector of the Short-Baseline Neutrino (SBN) Program, the ICARUS detector’s capability in searching for both muon neutrino disappearance and electron neutrino appearance will allow for unprecedented sensitivity to light sterile neutrinos with eV-scale mass. The ultimate sensitivity of the detector to sterile neutrino oscillations depends on the understanding of the detector response and the uncertainties remaining after calibrating the detector model. This poster will review how detector-model-related uncertainties are quantified, evaluated and their impact on expected sterile neutrino oscillation sensitivities using the existing ICARUS data. The work pursued here is broadly applicable to other ICARUS analysis pathways such as neutrino-argon cross-sections and Beyond the Standard Model physics searches. It will finally discuss improvement pathways to reduce the systematic uncertainties to the level needed for the joint sterile neutrino oscillation analysis with the Short Baseline Near Detector (SBND) within the SBN Program.
DUNE’s Near Detector utilizes new technological advancements for Liquid Argon (LAr) Time Project Chambers (TPC), including a modular design and pixel plane charge readout as opposed to the usual wire plane readouts. The full detector will be composed by 5x7 modules, but a demonstrator prototype with 2x2 modules is currently assembled and will take DUNE’s first neutrino beam data at Fermilab. A machine learning framework using convolutional and graph neural networks has been developed to reconstruct and identify particle footprints across the LAr modules. The demonstrator’s 2x2 LAr modules expect minimal containment of the particle tracks at its placement near the Neutrinos at the Main Injector (NuMI) beam source. Thus, some planes from the solid scintillator detector MINERvA have been repurposed to capture muon tracks upstream and downstream of the LAr 2x2 modules. This poster outlines DUNE’s current machine learning framework to reconstruct LAr TPC events and the potential to integrate data from a different detector medium to improve classification of particle clusters.
The Deep Underground Neutrino Experiment (DUNE) is a long-baseline, neutrino oscillation experiment designed to measure Charge Parity Violation in the neutrino sector using liquid argon as the primary detector medium. DUNE's main physics program is centered around measuring the flavor profile of beams in neutrino and anti-neutrino modes, as a function of energy, both at the near and the far detector, and will rely on accurate event reconstruction to do so. Understanding the detector response to neutrons will be critical for performing neutrino oscillation analyses in DUNE because they can elude detection resulting in missing energy. In addition to the primary neutrons produced in neutrino interactions, subsequent interactions of any charged hadrons produced can result in secondary neutrons. ProtoDUNE Single-Phase sits in a testbeam and is a 770-ton prototype of the DUNE far detector designed to validate technology and measure charged hadron cross sections at the relevant energies for DUNE; therefore, it is ideal for studying the secondary neutron component.
This talk presents the status of a neutron analysis using ProtoDUNE 1GeV/c pion data and prospects for two dedicated neutron-Argon total and capture cross section measurement experiments, namely, ARTIE-II at Los Alamos National Lab with sensitivity between 20-200 keV and the MArEx initiative at CERN aimed at measuring neutron cross sections up to a few tens of MeV.
Neutrino tagging is a new experimental method for accelerator based neutrino experiments. The method consists in associating a neutrino interaction with the meson decay (e.g. $\pi^\pm\to\mu^\pm \nu_\mu$ or $K^\pm\to\mu^\pm \nu_\mu$) in which the neutrino was originally produced. The properties of the neutrino can then be estimated kinematically from the decay incoming and outgoing charged particles. The reconstruction of these particles relies on the recent progress and developments in silicon particle detector technology. The method is particularly suited to study neutrino interactions at short baseline experiments, and preliminary works indicate that they could also be used to study neutrino oscillations at long baseline experiments.
A proof-of-principle of this method has been performed using the NA62 experiment as a miniature tagged neutrino experiment. Indeed, the intense Kaon beam of NA62 abundantly produces neutrinos through the $K^+\to\mu^+ \nu_\mu$ decay. The two spectrometers of the experiment are used to reconstruct the $K^+$ and $\mu^+$ and the neutrino interaction is detected in the 20 ton of liquid krypton of the electro-magnetic calorimeter. The results of the analysis based on the data collected in 2022 are presented, where few tagged neutrino candidates have been detected for the first time in history.
Sterile neutrinos, postulated as neutral leptons with no standard weak interactions, can be searched for through their mixing with active neutrinos in kinematic neutrino-mass experiments. The KArlsruhe TRItium Neutrino (KATRIN) experiment carries out precision tritium $\beta$-decay spectroscopy close to the kinematic endpoint. While the primary goal is the neutrino-mass measurement with a target sensitivity of 0.3 eV/$c^2$ (90% C.L.), we use KATRIN's data to search for light sterile neutrinos in a parameter range complementary to short-baseline neutrino oscillation experiments.
This poster presents the analysis of the five KATRIN science runs, highlighting the experiment’s unique sensitivity to a fourth mass eigenstate $m_{4}$ up to 40 eV and active-to-sterile mixing amplitude of $|U_{e4}|^2 \leq 0.5 $. Ongoing enhancements in statistics, background reduction and systematic uncertainty control expand coverage over relevant short-baseline oscillation anomaly regions.
ESSnuSB is a next-to-next generation long baseline neutrino oscillation experiment which aims to the precise measurement of the CP-violation in the leptonic sector studying neutrino oscillation at the second atmospheric maximum. The unique features of this experiment provide a great environment where to search for tiny new physics effects in neutrino oscillation beyond the three neutrino framework. Several scenarios have been recently studied in the ESSnuSB context. Among them, we show in this poster the ESSnuSB capabilities to explore the new physics parameters space in presence of scalar Non-Standard Interactions (sNSI) between neutrinos and ordinary matter. In addition to long-baseline physics, the ESSnuSB+ project proposes to explore neutrinos at short baseline using different Near Detectors. In this poster we also discuss the performances of these detectors in constraining sterile neutrino parameters employing neutrinos coming from two different beams: a low energy monitored beam (LEMNB) produced by pion decays and a low energy beam produced by muons circulating in a muon storage ring (LEnuSTORM).
LEGEND1000 is a ton scale experiment searching for neutrinoless double beta ($0\nu\beta\beta$) decay of $^{76}$Ge. The experiment uses High Purity Germanium (HPGe) crystals, which, enriched by $^{76}$Ge, serve as source and detector simultaneously. The discovery potential of LEGEND1000 lies at half-lives greater than $10^{28}$ years.
Due to the complexity of the data produced by this experiment, it becomes more and more attractive to analyze data with machine learning, as machine learning features can extract more information from data than classical analysis methods can. As an example, large germanium detectors, as the ones manufactured for LEGEND, exhibit a pulse shape dependence on the positions of the energy depositions. A reconstruction of these positions with classical methods is very limited. Therefore, a machine-learning-based approach is investigated, which analyzes the features of varying waveforms to create a position reconstruction algorithm.
The application of position reconstruction can provide an additional method for background reduction and has the potential to spot local impurities in the germanium crystal. The use of machine learning for position reconstruction additionally explores the possibilities of this technique in experimental physics.
This poster presents the current progress on a preliminary neural network to reconstruct Ge-detector event positions, which is trained and tested with simulated pulses. An optimized neural network may in future be applied to real data.
This work is supported by the U.S. DOE and the NSF, the LANL, ORNL and
LBNL LDRD programs; the European ERC and Horizon programs; the German
DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW;
the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Russian
RFBR; the Canadian NSERC and CFI; the LNGS, SNOLAB, and SURF
facilities.
CUORE is a ton-scale experiment designed for the search of the neutrinoless double beta ($0\nu\beta\beta$) decay of $^{130}$Te. Hosted in Italy at the Gran Sasso National Laboratory (LNGS), CUORE consists in an array of 988 cryogenic calorimeters operated below $\simeq$15 mK.
Experiments working at the millikelvin-scale are usually characterized by very good energy resolution. However, they have to handle and suppress many sources of noise, including electronic, vibrational and seismic noise.
The activity of seas and oceans is an additional, not yet extensively studied, source of noise, inducing microseismic waves in the sub-Hz domain.
This contribution will report a novel multi-detector analysis based on data from Copernicus Marine Environment Monitoring System (CMEMS), from high-sensitivity seismometers at LNGS, and from CUORE calorimeters.
We assess a strong correlation between variations in the Mediterranean Sea activity, in the microseismic noise at LNGS, and in the performance of all CUORE calorimeters. This correlation emphasizes the impact of microseismic noise generated by the Mediterranean Sea activity on the energy resolution of CUORE.
Since the energy resolution is a crucial parameter in defining the experimental sensitivity to $0\nu\beta\beta$ decay, the mitigation of such low-frequency environmental noise can benefit both CUORE and CUPID, the next-generation experiment for $0\nu\beta\beta$ decay searches with mK-calorimeters.
This analysis opens the possibility to improve noise-reduction algorithms, as well as to upgrade the seismic insulation system of the CUORE cryostat, which will also host the CUPID experiment.
The IceCube Neutrino Observatory is a one-cubic-kilometer-sized neutrino telescope deployed in the deep Antarctic ice at the South Pole. One of IceCube’s major goals is finding the origin of astrophysical high-energy neutrinos. In 2022, IceCube published the results of a search for astrophysical point-like sources of neutrinos in the Northern Sky using 9 years of events produced by charged-current muon-neutrino interactions. These events provide good pointing precision, making the sample optimal for point-source searches. This analysis identified the active galaxy NGC1068 as a candidate source of astrophysical neutrinos with a global significance of 4.2$~\sigma$. NGC1068 is classified as a Seyfert galaxy, and it is especially bright in the X-ray emission band. This result contributed to raise the interest in this particular class of active galaxies as a potential population of neutrino emitters. In this poster, we present the extension of the previous analysis using 13 years of data and, given the particular nature of NGC1068, we also perform a search for neutrino emission focusing on X-ray bright Seyfert Galaxies.
The search for neutrinoless double beta decay is crucial to shed light on neutrino properties and broader cosmological questions. Experiments utilizing the isotope 76Ge have been essential in advancing the sensitivity to neutrinolsess double beta decay. The LEGEND project uses High Purity Germanium (HPGe) detectors and minimize background interference through the application of Pulse Shape Analysis (PSA) significantly. To further refine this process, we tested the adoption of a Neural Network enhanced by Feature Importance Supervision (FIS) adjusted for PSA in HPGe detectors. This approach integrates expert knowledge on waveform characteristics, enabling the model to tag signal from background noise without energy dependence. It has demonstrated considerable success in differentiating between the multi-site gamma radiation that forms
background noise and the single-site signals indicative of neutrinoless double beta decay. In this poster, I will present the current status of the approach under development.
This work is supported by the U.S. DOE and the NSF, the LANL, ORNL and LBNL LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Russian RFBR; the Canadian NSERC and CFI; the LNGS, SNOLAB, and SURF facilities.
As more measurements on various event topologies of neutrino-nucleus interactions become available, Monte Carlo (MC) prediction from neutrino event generators, such as GENIE, shows considerable deviation from some data sets while matching others relatively well. In this work, we present the first global analysis, enabled by the GENIE global analysis framework, of four Transverse Kinematic Imbalance (TKI) measurements on carbon targets with and without pion production, namely $\nu_\mu CC0\pi Np$ and $\nu_\mu CC1\pi^+ Np$ from T2K and $\nu_{\mu}CC0\pi Np$ and $\nu_\mu CC M\pi^0 Np$ from MINERvA, where $M,N\geq1$. In both T2K and MINERvA data releases, the authors benchmarked their data against GENIE predictions, except for MINERvA’s $\pi^0$, in which a GENIE comparison is absent. In the reported benchmarking, GENIE predictions agree relatively well with T2K’s $\nu_\mu CC0\pi Np$ and $\nu_\mu CC1\pi^+ Np$ as well as MINERvA’s $\nu_\mu CC0\pi Np$ measurements. We use the GENIE global analysis framework with the latest GENIE tune, G24_20i_00_000. The prediction describes the first three measurements considerably well, but it overpredicts MINERvA’s $\pi^0$. As the TKI variables are excellent probes for nuclear initial states and final state interactions (FSI), we performed a tuning on the reliable Local Fermi Gas (LFG) nuclear model and the hA INTRANUKE FSI model using GENIE Comparisons interfaced with PROFESSOR. The tuning exercise serves as a proof-of-concept practice of using TKI data with and without pion production to constrain model parameters, and the result is stored in a new GENIE tune, G24_20i_06_22c. It gives significantly better prediction for the single $\pi^0$ production sample while keeping the same level of data-MC agreement for $0\pi$ and $1\pi^+$ datasets. This is accomplished mainly by suppressing $\pi^0$ mean free path and the pion charge exchange in FSI. The success of this tuning bolsters the viability of our method and highlights a workable path towards continual model tuning.
This poster presents new results from the first joint oscillation analysis of atmospheric neutrinos at Super-Kamiokande (Super-K) and accelerator neutrinos at Tokai-to-Kamioka (T2K). Leveraging Super-K atmospheric neutrinos, which are sensitive to mass ordering, and T2K accelerator neutrinos, which are sensitive to the CP violation phase, the joint analysis is able to improve sensitivity by resolving degeneracies between these parameters. This poster presents frequentist and Bayesian results for the neutrino mass ordering, CP violation phase, as well as other mixing parameters. For the test of CP-conservation, a dedicated p-value is introduced with improved statistical properties compared to what can be obtained using confidence intervals on the CP-violation phase. An analysis of the statistical consistency between Super-K and T2K is performed under the common systematic uncertainty model which incorporates correlations between the two experiments. The potential of future joint fits is finally studied using the expected sensitivities on oscillation parameters.
KM3NeT/ORCA is a water Cherenkov neutrino telescope under construction in the Mediterranean sea. With ORCA, the KM3NeT collaboration will measure atmospheric neutrino oscillations to determine the neutrino mass ordering and constrain the oscillation parameters $Δm_{31}^2$ and $θ_{23}$. In addition, Beyond the Standard Model hypotheses can be tested. In this contribution, the sensitivity of ORCA to the presence of a light sterile neutrino in a 3+1 model is presented, as well as the first measurements of the active-sterile mixing parameters. Using 433 kton-yr of data-taking with a partial configuration of only 5% of the final detector, ORCA is able to constrain the active-sterile mixing angles $θ_{24}$ and $θ_{34}$. Two sets of scenarios are explored. First, $θ_{24}$ and $θ_{34}$ are simultaneously constrained under the assumption of an eV-mass sterile neutrino, which is one possible explanation to the anomaly seen in short baseline neutrino experiments. Then, each mixing angle is individually constrained over a broad range of mass squared difference $∆m_{41}^2$~[10⁻⁴,10] eV² to probe the hypothesis of a very light sterile neutrino.
This poster presents the first measurement of cosmogenic $^8$He isotope production in liquid scintillator at Daya Bay, using an innovative method for identifying cascade decays of $^8$He and its child isotope, $^8$Li. We also measure the production yield of $^9$Li isotopes using two independent methods. The results, in units of $10^{-8}\mu^{-1}\rm g^{-1}cm^{2}$, are 0.307$\pm$0.042, 0.341$\pm$0.040, and 0.546$\pm$0.076 for $^8$He, and 6.73$\pm$0.73, 6.75$\pm$0.70, and 13.74$\pm$0.82 for $^9$Li at average muon energies of 63.9 GeV, 64.7 GeV, and 143.0 GeV, respectively. These results supersede previous attempts to determine the ratio of $^8$He to $^9$Li production, which yielded a wide range of limits from 0 to 30%. They also provide future liquid scintillator-based experiments with improved ability to predict cosmogenic backgrounds.
LEGEND-200 is an experiment designed to search for neutrinoless double beta decay ($0\nu\beta\beta$) in $^{76}$Ge at LNGS in Italy. The sensitivity of $0\nu\beta\beta$ experiments is strongly affected by the background level. LEGEND-200 aims to reach a background index of $2\times 10^{-4}$ counts/keV/kg/yr at $Q_{\beta\beta}$. With an exposure of 1 tonne-yr this would lead to a half-life sensitivity of more than $10^{27}$ yrs. In this poster, we present a detailed model of the background sources in the LEGEND-200 experiment by fitting the experimental data over a wide spectral range to a sum of Monte-Carlo simulations. This work informs future hardware upgrades of LEGEND-200, the design of LEGEND-1000 and enables a series of beyond Standard Model physics searches.
This work is supported by: U.S. DOE, NSF, LANL, ORNL, LBNL LDRD programs; European ERC, Horizon programs; German MPG, BMBF, DFG; Italian INFN; Polish NCN, MNiSW; Czech MEYS; Slovak SRDA; Swiss SNF; UK STFC; Russian RFBR; Canadian NSERC, CFI; LNGS, SNOLAB and SURF facilities.
The Tokai to Kamioka (T2K) experiment is a long baseline neutrino experiment in Japan which aims to measure neutrino oscillation parameters with world leading precision. One of the most profound and challenging tasks facing T2K is determining whether or not CP symmetry is violated in the lepton sector.
In order to perform these measurements, we require excellent constraints on systematic uncertainties relating to the initially unoscillated neutrino beam, as well as on neutrino nucleus interactions that occur in the detector media. Data collected at T2K's near detector (ND280) is used to greatly improve these constraints by fitting parameters of a highly sophisticated model.
There have been many upgrades to this analysis recently. These include an overhaul of the modelling of detector systematic uncertainties, moving towards a more easily interpretable approach which uses fewer simplifying assumptions. In order to better constrain this new model, new analysis samples have also been introduced with better angular acceptance.
These improvements will be summarised in this poster, and fit results of this model to ND280 data using a Markov chain Monte Carlo approach will be shown.
The search for neutrinos with energies greater than $10^{17}~$eV is being actively pursued. Although normalization of the dominant neutrino flux is highly uncertain, a floor level is guaranteed by the interactions of extragalactic cosmic rays with Milky Way gas. We estimate that this floor level gives an energy flux of $E^2\phi_\nu\simeq 10^{-13^{+0.5}_{-0.5}}~$GeV~cm$^{-2}$~sr$^{-1}$~s$^{-1}$ at $10^{18}~$eV, where uncertainties arise from the modeling of the gas distribution and the experimental determination of the mass composition of ultra-high-energy cosmic rays on Earth. Based on a minimal model of cosmic-ray production to explain the mass-discriminated energy spectra observed on Earth above $5{\times}10^{18}$~eV, we also present generic estimates of the neutrino fluxes expected from extragalactic production that generally exceed the aforementioned guaranteed floor. The prospects for detecting neutrinos above $10^{18}$~eV remain however challenging, unless proton acceleration to the highest energies is at play in a sub-dominant population of cosmic-ray sources or new physical phenomena are at work.
In 2021, the MAJORANA DEMONSTRATOR experiment concluded its investigation into neutrinoless double beta decay involving $^{76}$Ge. Proven to be one of the world's ultra-low-background facilities, we adapted the apparatus to explore the rare decay of a distinct isotope. Notably, in nature $^{180m}$Ta stands as the sole known isotope existing in an isomeric state rather than the ground state. This unobserved isomeric decay is hindered by spin suppression. However, measuring its rate will provide insight into the strength of its production, for example, through neutrino-induced reactions. Beyond understanding the underlying mechanisms of the decay this exceptional state, a measurement of the decay rate holds potential of probing dark matter through stimulated decay as an complimentary effort. To this end, we introduced Ta samples amidst the Ge detectors, capitalizing on the deep-underground ultra-low background environment, the exceptional energy resolution of the MAJORANA detectors, and established analytical methodologies to search for both, the nuclear decay and potential dark matter-induced emissions. The first year of data was dominated by backgrounds from surface activation of the Ta-samples yet still was able to set world-leading limits. I plan to present the findings from our latest data collection and discuss their implications for the dark sector.
This material is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics and Nuclear Physics Programs of the National Science Foundation, and the Sanford Underground Research Facility. We acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program.
The KM3NeT next generation deep-sea neutrino telescopes are currently under construction in the Mediterranean Sea. Two water-Cherenkov neutrino detectors, ARCA and ORCA, are located in two different sites, south-est of Portopalo di Capopassero (Italy) and close to Toulon (France), respectively. The KM3NeT/ARCA telescope, a cubic kilometer volume detector, is optimised for the detection of high-energy astrophysical neutrinos in the TeV-PeV range. Once completed, the detector will consist of 230 Detection Units, each housing 18 Optical Modules. In order to search for neutrino signals, a high background rejection power is needed and deep learning techniques provide promising methods for achieving this result. The flexibility of the so-called Graph Neural Networks (GNNs) suits perfectly the topology of a complex detector such as KM3NeT.
This contribution will be focused on two interesting applications of GNNs: discrimination of signal events from the background, mainly composed of atmospheric induced events, and energy and direction event reconstruction.
Long baseline neutrino experiments are moving toward precision measurements of the oscillation parameters; namely the CP violation phase, the mass ordering or the octant of $\theta_{23}$. This means systematic uncertainties must be reduced to few percent level, especially those related to neutrino interactions. This is usually done by using near detector data to constrain theoretical models. As a result, statistical analyses for neutrino interaction model tuning and neutrino cross-section measurements now involve near a thousand nuisance parameters with increasingly more complex functions for propagating systematic errors. In addition, combined experiment analyses carried out recently have revealed the crucial need for developing common software tools for achieving the next world leading measurements of oscillation parameters. In the context of the upgrade of the near detectors of T2K, we designed a pioneering open-source tool called GUNDAM, standing for Generalized and Unified Neutrino Data Analysis Methods. Its ambition is to provide a universal software suite for performing any statistical analysis. Its unique structure allows physicists to compose their own analysis without editing the source code i.e., only using a set of configuration files and inputs. The T2K collaboration is now using GUNDAM as its main frequentist fitter for performing model tuning and cross-section analyses at the near detector. This poster presents the main features and design of GUNDAM, as well as its most recent achievements with T2K data. Upcoming functionalities will be advertised, such as Bayesian MCMC engine or the perspective of performing a full oscillation analysis, using simultaneously the near and the far detector data.
Following the exciting discovery of astrophysical neutrinos and subsequent studies of their origins by IceCube, future improved all-flavor neutrino detection would allow for a strong probe into the abundant physics lying within these astrophysical sources. The main challenge in flavor identification is to break the degeneracy among cascade events and separate out the interactions due to tau neutrinos. In 2020, two tau neutrino candidates observed by IceCube demonstrated the great potential using waveforms to do particle identification in neutrinio telescopes. TRIDENT is a next-generation water-based neutrino telescope, incorporating Hybrid Digital Optical Modules (hDOM) with multi-channel PMTs and SiPMs. This system expects to enhance the sensitivity to tau neutrinos by providing larger photon coverage and independent waveform readout, fully leveraging the low optical scattering in seawater. Here, we present the latest progress of tau classification in TRIDENT using waveform techniques.
MicroBooNE, a Liquid Argon Time Projection Chamber (LArTPC) located in the $\nu_{\mu}$-dominated Booster Neutrino Beam at Fermilab, has been studying $\nu_{e}$ charged-current (CC) interaction rates to shed light on the MiniBooNE low energy excess. The LArTPC technology employed by MicroBooNE provides the capability to image neutrino interactions with mm-scale precision. Computer vision and other machine learning techniques are promising tools for image processing that could boost efficiencies for selecting $\nu_{e}$-CC and other rare signals, reduce cosmic and beam-induced backgrounds, and improve the reconstruction of neutrino energies. The MicroBooNE experiment has been at the forefront of developing and testing such techniques for use in physics analyses. In this poster we overview deep-learning based reconstruction methods. We will showcase the use of a recurrent neural network to estimate neutrino energies and present a new reconstruction framework that uses convolutional neural networks to locate neutrino interaction vertices, tag pixels with track and shower labels, and perform particle identification on reconstructed clusters. We will present studies characterizing the performance of these new tools and demonstrate their effectiveness through their use in an inclusive $\nu_{e}$-CC event selection.
The reliable estimation of accelerator neutrino beam fluxes is important for precise neutrino oscillation measurements in searching for CP violation in the leptonic sector. In long-baseline neutrino experiments, the neutrino flux uncertainties contribute significantly to uncertainties in neutrino oscillation parameters. Hadron production is the largest component of the flux uncertainty, so secondary interactions with materials in the beamline should be considered for better precision. One of the main components of the flux uncertainty from material modeling in the beamline is the interactions of hadrons with the cooling water inside the magnetic horns, which contributes a ~3% uncertainty. The secondary interaction between the cooling water and the neutrino's parent particle is responsible for this, but the effect was not well known. The cooling water is sprayed directly from the outer conductor of the magnetic horn toward the inner conductor, so the water distribution is constantly varying. To estimate the water distribution in more detail compared to the previous estimation, a horn mock-up was made and the water thickness was measured by modeling the cooling water distribution using image analysis. This analysis improved the flux uncertainty around the flux peak (600MeV) by more than 1% compared to the previous error estimation. The results are incorporated into neutrino beam simulations to estimate systematic uncertainties in the flux, and it is expected to improve the precision of the T2K neutrino oscillation analysis. The study will also be useful for HK and other future experiments. In this poster, an analysis development method to estimate the water distribution with image analysis and an improved T2K flux precision with the result are described.
Identification of background radiation is of utmost importance for enabling rare event experiments. The Neutrinoless double beta decay experiment LEGEND, utilizes background suppression to reach sensitivities of $T_{1/2}>10^{28}$yrs with the isotope $^{76}$Ge. Poly(ethylene-2,6-naphthalate) (PEN) has emerged as a highly promising material for LEGEND due to its intrinsic scintillating properties and its structural behavior at both room and cryogenic temperatures.
PEN has been successfully implemented in the LEGEND-200 experiment as both an active material and a structural component within the detector assembly. Looking towards the next-generation experiment, LEGEND-1000 will further reduce background radiation to <10$^{-5}$ cts/(keV kg yr). To achieve this goal, we are looking to produce custom PEN-G and expand potential applications to further improve background radiation identification. In this presentation, we will present the optical properties and radiopurity of custom synthesized PEN, and potential impact on applications in LEGEND-200 and LEGEND-1000.
This work is supported by the U.S. DOE and the NSF, the LANL, ORNL and LBNL LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Russian RFBR; the Canadian NSERC and CFI; the LNGS, SNOLAB, and SURF facilities
The NOvA experiment’s most recent search for eV-scale sterile neutrinos is systematically limited in the region of parameter space where $\Delta m^2_{41} \gtrsim 1~\mathrm{eV}^2$. This region of parameter space is preferred by sterile neutrino interpretations of current experimental anomalies; improving sensitivity here is high-priority. When added directly into the fit, additional data samples which are subject to orthogonal systematic uncertainties act as in-situ constraints, breaking the degeneracy between systematic uncertainties and sterile-induced oscillations. The NOvA experiment consists of two functionally identical detectors, 14.6 mrad off-axis of the NuMI beam, with the Near Detector (Far Detector) 1 km (810 km) from the beam source. The Near Detector’s position on-site at Fermilab means that it is also able to observe neutrinos from a second neutrino beam, the BNB, 160 mrad off-axis. NOvA has been taking BNB data since 2015, but has not yet analysed these data. The BNB and NuMI are subject to different beam-related uncertainties, allowing us to leverage this sample as an in-situ constraint. This poster will present the current status, preliminary simulations, and potential additional uses of this unique experimental setup
Cryogenic calorimeters are particle detectors that measure energy as a temperature rise. To achieve adequate sensitivity, they must be operated at $\sim$10mK, where they achieve optimum energy resolution. When using a scintillating crystal as a particle absorber, reading the scintillation light from a second cryocalorimeter provides particle identification. Both elements have NTD thermistors for temperature change readout.
These detectors have proven to be a powerful tool for current (e.g. CUORE) and future (e.g. CUPID) experiments in the rare element research landscape.
We have been testing innovative solutions for different elements of the detector to assess the possibility of achieving higher sensitivities and better light collection, resulting in increased performance and better background discrimination.
To reduce detector response time, we tested NTDs fabricated using $^{11}$B and $^{10}$B implantation. It is expected that the sensitivity and response time of the calorimeters will be affected by the different low-temperature specific heats of these materials. We have tested calorimeters in operation with different NTDs and have evaluated the effect on detector performance.
To improve scintillation light collection and thus background discrimination, we operated Li$_2$MoO$_4$ scintillating calorimeters coated with Al.
In order to increase the response of the light detector, we are designing transparent electrodes to implement the phonon amplification by charge drift (Neganov-Trofimov-Luke effect) and we are testing the possibility of using photosensitive thin films to increase the light collection efficiency.
We will show the performance, measured at the Milano~-~Bicocca Cryogenic Laboratory, of several thermal detectors realised with the aforementioned novel techniques in the framework of CUPID R\&D.
Underwater or in-ice neutrino oscillation experiments, which detect the products of neutrino interactions via Cherenkov radiation, have traditionally reconstructed events using a ‘track’ or ‘shower’ event classification scheme. At the neutrino energies of interest to these experiments, deep inelastic scattering is the dominant interaction mechanism. As a result, a hadronic shower is always created at the vertex of charged-current interactions, alongside the out-going lepton. This work presents a dedicated ‘track+shower’ reconstruction algorithm, which aims to more completely describe neutrino interactions in the KM3NeT research infrastructure.
The potential of this algorithm in performing particle identification for simulated neutrino events in the ORCA-6 sub-detector is presented. In turn, the improved neutrino energy resolution and directly-reconstructed Bjorken-y for neutrino events in the envisaged ORCA detector is shown. Such an algorithm paves the way for future neutrino oscillation analyses in KM3NeT, with improved energy resolution and reconstructed Bjorken-y being essential tools for a determination of the neutrino oscillation parameters and the yet-unknown Neutrino Mass Ordering.
Jiangmen Underground Neutrino Observatory (JUNO), under construction in South China, is designed to resolve the neutrino mass ordering using the oscillatory pattern of the electron anti-neutrinos produced in nuclear reactor cores. With a baseline of 52.5 km and a fine energy resolution of 3% at 1 MeV, JUNO will allow for the observation of two neutrino oscillation modes simultaneously, collecting about 100,000 inverse beta-decay events in six years with a 20 kton liquid scintillator target. This makes it possible to precisely measure the mixing angle $\theta_{12}$ and mass splittings $\Delta m^2_{21}$ and $\Delta m^2_{31}$ with unprecedented accuracy below 1%. The poster will cover details of the analysis and the final sensitivity results.
Core-collapse supernovae (CCSNe), the explosions marking the end of a massive star’s life cycle, are of immense interest in astrophysics but their underlying mechanism is not completely understood yet. Given the high density and opacity of the star’s core, neutrinos emerge as the most promising probe for unravelling the CCSN dynamics. However, such neutrinos would be detected only if a supernova takes place in our Galaxy or its neighbourhood. Since close-by CCSNe are rare and unpredictable, it is necessary to maximize the detection potential of all sensitive neutrino experiments. We present an updated CCSN search strategy using the KM3NeT neutrino detector.
KM3NeT, currently being deployed in the Mediterranean Sea, was initially designed for the detection of GeV to PeV neutrinos. However, its spherical digital optical modules (DOMs), equipped with 31 photomultipliers oriented in various directions, can be used as standalone detectors for MeV-scale CCSN neutrinos. To identify these neutrinos, we defined new observables that characterize the geometry of events on single DOMs. These observables allow discerning low-energy neutrino events associated with CCSNe from radioactive decays in seawater and atmospheric muons. We will present the sensitivity of KM3NeT’s current and final detector configurations to the next close-by CCSN, using the single-DOM observables to maximize the signal-to-noise ratio. In addition, we will show how to parameterize the variations of the expected background level with the data-taking conditions. This parameterization is essential to search for CCSNe automatically with KM3NeT’s Real-Time Analysis Platform.
Hyper-Kamiokande is the next generation Water Cherenkov experiment in Japan, which will study with unprecedented precision the oscillations of different types of neutrinos, as well as neutrinos of astrophysics origin. The inner part of this massive new detector will be instrumented with 20000 high precision photomultiplier tubes (PMT). The R12860 PMT was developed by Hamamatsu Photonics for the Hyper-Kamiokande project, and has improved timing resolution, detection efficiency and charge resolution compared to the model used in the current Super-Kamiokande experiment. The mass production of these PMTs is on-going, and as part of the quality assurance process of Hyper-Kamiokande, a fraction of them are measured over one month periods in two specially built setups to evaluate their performance, check they satisfy the requirements of the experiment and detect any possible variation of the production quality during mass production. In particular, one of the setups allows us to measure the dark rate, after-pulse, timing and charge resolution of 16 PMTs at a time, as well as evaluate the stability of the PMTs performance over one month. The regular measurements done during the mass production provide large statistics measurements to characterize the performance of the R12860 PMT. We will present the results of the measurements in this poster, together with the setups used.
Building upon the LEGEND-200 experimental program, LEGEND-1000 is an upcoming ton-scale experiment in search of Neutrinoless Double Beta Decay ($0\nu\beta\beta$). Consisting of over 300 $\sim$3 kg germanium detectors surrounded by an instrumented liquid argon shield, L-1000 aims to make a 99.7% CL discovery of $0\nu\beta\beta$ with sensitivity covering the full inverted neutrino mass ordering, a $10^{28}$ yr half-life discovery potential after 10 years of exposure. We present the progress of the conceptual design of L-1000 and site preparation, and materials sourcing and deployment timeline. L-1000 will utilize 1000 kg of $^{76}$Ge-enriched high purity germanium (HPGe) semiconductor detectors, whose large mass is enabled by the inverted-coaxial point contact (ICPC) design. We review detector characterization efforts for L-1000, including avenues of characterization R&D.
This work is supported by the U.S. DOE and the NSF, the LANL, ORNL and LBNL LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Russian RFBR; the Canadian NSERC and CFI; the LNGS, SNOLAB, and SURF facilities.
We explore the connection between low-scale CP-violating Dirac phase $(\delta)$ and high-scale leptogenesis in a Left-Right Symmetric Model (LRSM) with scalar bidoublet and doublets. The fermion sector of the model is extended with one sterile neutrino $(S_L)$ per generation to implement a double seesaw mechanism in the neutral fermion mass matrix. The double seesaw is performed via the implementation of the type-I seesaw twice. The first seesaw facilitates the generation of Majorana mass term for heavy right-handed (RH) neutrinos $(N_R)$, and the light neutrino mass becomes linearly dependent on $S_L$ mass in the second. In our framework, we have taken charge conjugation ($C$) as the discrete left-right (LR) symmetry. This choice assists in deriving the Dirac neutrino mass matrix ($M_D$) in terms of the light and heavy RH neutrino masses and light neutrino mixing matrix $U_{PMNS}$ (containing $\delta$). We illustrate the viability of unflavored thermal leptogenesis via the decay of RH neutrinos by using the obtained $M_D$ with the masses of RH neutrinos as input parameters. A complete analysis of the Boltzmann equations describing the asymmetry evolution is performed in the unflavored regime, and it is shown that with or without Majorana phases, the CP-violating Dirac phase is sufficient to produce the required asymmetry in the leptonic sector within this framework for a given choice of input parameters. Finally, we comment on the possibility of constraining our model with the current and near-future oscillation experiments, which are aimed at refining the value of $\delta$.
We report recent progress on a LiF Experiment for keV Sterile Neutrino Search (LiFE-SNS) based on tritium beta decay measurement at mK temperatures. We use LiF crystals with $^3$H embedded through the Li(n,$\alpha$)$^3$H process. Magnetic microcalorimeters, one of the high-resolution detector technologies, are adopted to measure the amount of the energy deposited into the crystal absorber from $^3$H beta decays. Two detector modules have been prepared for the first phase of the project to achieve the highest sensitivity near the 10-keV region with a four-month measurement period. In this poster, we present the short- and long-term goals of the LiFE-SNS project searching for keV-scale sterile neutrinos together with possible systematics.
The Deep Underground Neutrino Detector (DUNE) is a long-baseline neutrino oscillation experiment currently under construction at the Sanford Underground Research Facility, with a near detector planned for installation at Fermi National Laboratory. Prototypes for Near and Far Detector components have already recorded data from cosmic rays and mixed hadron beams; however, the 2x2 Demonstrator, currently installed at Fermi National Laboratory and slated to collect data in the Spring of 2024, will be the first DUNE prototype to collect data from a neutrino beam. Composed of four integrated, single-phase, 600 kg liquid argon modules, the 2x2 Demonstrator prototypes the modular design of the DUNE Liquid Argon Near Detector in beamline conditions. The 2x2’s four modules are bisected into eight optically isolated time projection chambers (TPCs), each of which contains a pixelated charge readout, as well as 16 wavelength shifting light traps coupled to 48 silicon photomultiplier channels. This light readout system is optimized to mitigate event pileup through the precise timing of interactions in each TPC volume. Placed within each TPC’s field structure to maximize light yield, the 2x2’s high-coverage light traps provide localized timing resolution on the order of nanoseconds. This poster gives an overview of the 2x2 Demonstrator’s light readout system: its design, its initial performance collecting cosmic ray data, and its efficacy in a high-intensity beam environment.
One of the longest-standing sterile neutrino anomalies is the Gallium anomaly in which transition from electron neutrino to sterile neutrino oscillation on the meter scale has been suggested as a solution to measured electron neutrino deficit originally observed in GALLEX and SAGE experiments, and more recently in the BEST experiment in which a 4 sigma significant deficit of electron neutrinos from the 51-Cr source was measured. Contrary to the reactor neutrino experiments where the expected flux is estimated from thousands of beta decay branches, neutrinos from a strong source feature well-understood spectrum due to a single radioactive process and flux extrapolated from the strength of the source. To search for meter-scale oscillations to sterile neutrinos with electron antineutrinos in KamLAND we propose LiLAND experiment that will utilize electron antineutrinos from the beta decay of 8-Li. 8-Li has a well-known spectrum with 13 MeV end-point, mostly above radiogenic backgrounds, making it a very attractive source of MeV antineutrinos. A similar idea has been previously proposed by IsoDAR experiment. Unique to LiLAND that we proposed, is the production mechanism of 8-Li. 8-Li will be produced in situ by irradiating 7-Li sleeve with neutrons produced by a high-power DT neutron generator at its core. This idea has been enabled by a recent development of very powerful DT generators with a yield of the order $10^{13}$ neutrons/s. We will present initial considerations, conceptual design, and expected rates. Of utmost importance is to place the source as close to KamLAND volume to increase sensitivity to to increase sensitivity to higher neutrino mass region favored by BEST result.
The LEGEND-200 experiment at Laboratori Nazionali del Gran Sasso, is designed to search
for neutrinoless double beta decay of 76Ge. The experiment uses about 200 kg of high-purity
germanium (HPGe) detectors, enriched in 76Ge, deployed within a cryostat filled with liquid
argon (LAr). The LAr acts as a cooling medium and as an active shield. The LAr
instrumentation is deployed in LEGEND-200 to detect the LAr scintillation light emitted by
background nuclear processes occurring within the LAr and that accompany signal response
in the HPGe detectors. Background events originate from α-, β-, γ- or neutron interactions,
coming from primordial, anthropogenic or cosmogenic unstable isotopes. They may impact
the detection of neutrinoless double beta decay signals, which involve energy deposition
inside the HPGe detectors, with no corresponding energy deposition occurring in the LAr.
The poster will cover the LAr instrumentation setup, the performance during
commissioning and physics runs. The Event Topology Classifier (ETC) utilized to
discriminate between β/γ and α radiation will also be presented. We showcase the ETC’s
role in tagging delayed Po-alphas depositing energy in the LAr following prompt signals of
Bi-gammas detected in the HPGe detectors.
This work is supported by the U.S. DOE and the NSF, the LANL, ORNL and LBNL
LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and
MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA;
the Swiss SNF; the UK STFC; the Russian RFBR; the Canadian NSERC and CFI; the
LNGS, SNOLAB, and SURF facilities.
The Cryogenic Underground Observatory for Rare Events (CUORE) is a bolometric neutrinoless double-beta ($0\nu\beta\beta$) experiment, which has collected over 2 Tonne$\cdot$years of TeO$_2$ exposure. CUORE’s primary analysis of searching for $0\nu\beta\beta$ in $^{130}$Te has an energy region of interest at $\sim$ 2,500 keV. CUORE’s extremely low background levels, high energy resolution, and exposure make multiple other rare event searches possible. New data analysis tools and studies enable searches in CUORE’s low energy region below 100 keV, two orders of magnitude below the $0\nu\beta\beta$ region of interest.
Searches in CUORE’s low energy region, such as for low mass dark matter and solar axions, could provide new insights and complement other particle physics searches. Previous CUORE studies typically use an analysis threshold of 40 keV for searches. Lowering this threshold, along with a better understanding of low-energy events and backgrounds, improves knowledge of background and coincidence events for all searches. This contribution describes analysis methods developed for the CUORE low energy region. It will also detail a search for solar axions or Axion Like Particles (ALPs), well-motivated dark matter candidates that could provide a solution for the QCD Strong CP problem. This analysis implements these tools as a first search in this energy region with CUORE.
The MicroBooNE detector is a liquid argon TPC located in the Booster Neutrino Beamline at Fermilab. Leveraging the unique capabilities of the LArTPC technology to distinguish photons from electron showers, one of MicroBooNE's primary goals is to investigate MiniBooNE low energy excess (LEE), an anomalously large observed rate of events containing a single electromagnetic shower. This electromagnetic shower could be caused by electrons, photons, or electron-positron (e+e-) pairs, which would all look very similar in the MiniBooNE Cherenkov detector, but could have distinct signatures in the MicroBooNE LArTPC. In this poster, we present an updated and new search for these signals, including searches for electron neutrino, single-photons, and e+e- pairs.
Radioanalytical chemistry methods and techniques have recently been widely involved in very low-level radioactivity measurements for physics experiments searching for extremely rare events. All experiments searching for events with elusive rates are bound by the unavoidable necessity to reduce to zero background levels and enlarge a target material to identify feeble signals. The need to minimize the background level while maximizing detector exposure leads to the pivotal importance of the implications of radioanalytical chemistry methods: radioassay of detector components and shielding materials at ultra-low levels, purification of target materials, and selective separation of interfering radioactive impurities, reduction of surface contamination, cooperation of extraction methods with the radioactivity counting methods, etc. In this work, the radioanalytical chemistry contribution to pioneering and leading physics experiments will be highlighted. The emphasis will be placed on solid-phase extraction (SPE) combined with ICP-MS, HPGe, NAA, etc. techniques applied to reach Th and U detection sensitivity at sub-ppt and ppq levels. The results of materials purification and radioassay obtained for AMoRE collaboration using the ICP-MS/SPE combination will be presented, along with a comparative summarization of the sensitivity achievements of other experimental groups.
The Search for Hidden Particles (SHiP) experiment will be the new flagship project of the CERN Physics Beyond Colliders intensity frontier, featuring a dedicated Beam Dump Facility (BDF) at CERN's North Area ECN3 to exploit the full potential of the 400 GeV SPS proton beam.
The experiment is realised by a two-fold detector setup enabling a diverse physics program: While the Hidden Sector (HS) detector will study the decay of Heavy Neutral Leptons (HNL) and other Feebly-Interacting Particles (FIPs) in a broad range of masses and coupling inaccessible to colliders, the upstream Scattering and Neutrino Detector (SND) is going to enable a direct search for Light Dark Matter (LDM), as well as measurements in neutrino physics with unprecedented precision.
As the detector is located closely downstream of the dense proton beam target, a major challenge will be the reduction of beam-related backgrounds. Following a hadron stopper, the superconducting magnet muon shield will deflect most of these particles from the detector acceptance, but muon and neutrino interactions in the detector and its vicinity still have to be correctly discriminated. To this end, the 50 m-long evacuated volume of the HS decay vessel will be enveloped with a Surrounding Background Tagger (SBT) consisting of O(1 000) cells filled with Liquid Scintillator (LS) and equipped with Wavelength-Shifting Optical Modules (WOMs) and SiPM readout.
This contribution will provide details on the specifications and technology of the LS-SBT, showcasing the performance of prototype detectors in several test beam exposures.
Having just been approved by the CERN Research Board, this is the ideal time for new groups to join the project.
One of the primary oscillation physics goals of the Deep Underground Neutrino Experiment (DUNE) far detector (FD) is the measurement of CP violation in the neutrino sector. To achieve this, DUNE plans to employ large-scale liquid-argon time-projection chamber technology to capture neutrino interactions in unprecedented detail. Such fine-grain images demand a highly sophisticated automated reconstruction software such as Pandora to unlock the potential for a highly efficient and pure selection of charge-current (CC) muon/electron neutrino interactions. This poster presents the Pandora-based CC muon/electron neutrino interaction selection and explores its employed particle-identification methods, which range from simple boosted-decision trees to more complex deep learning approaches. This work illustrates the reconstruction-to-analysis continuum, via which specific Pandora reconstruction improvements are motivated and targeted, moving DUNE ever closer to uncovering the mysteries of neutrinos.
Cosmic muon interactions leading to the in-situ production of long-lived radioisotopes may introduce a significant background in the context of rare event searches conducted deep underground. Specifically, the delayed decay of $^{77(m)}$Ge emerges as the primary contributor from in-situ cosmogenic sources for the neutrinoless double-beta decay search with $^{76}$Ge. The future LEGEND-1000 experiment, aiming for a ton-scale setup, necessitates a stringent requirement of a total background less than $10^{-5} \rm cts/(keV\cdot kg \cdot yr)$. Neutron backgrounds are closely tied to factors such as laboratory depth, shielding material, and cryostat design. The incorporation of passive neutron moderators results in a reduced background contribution. In order to determine the most effective shield design, computationally intensive Geant4 Monte Carlo simulations need to be generated multiple times to probe the high-dimensional parameter spaces. Traditional Monte Carlo simulations, however, may prove time-consuming and challenging when addressing full optimization across numerous parameter spaces. This renders conventional methods, such as grid searches, computationally infeasible. Machine learning emerges as a valuable tool, not only for accelerating common modeling but also for minimizing the reliance on computationally expensive standard Monte Carlo methods. We outline a Multi-Fidelity Gaussian Process study, showcasing its application in a small-scale context based on various neutron moderator configurations. The approach presented holds the potential for adaptability in exploring alternative detector shielding designs for $^{76}$Ge experiments, such as LEGEND.
SNO+ is an operational kiloton-scale multipurpose neutrino experiment loaded with linear alkylbenzene-based scintillator. SNO+ analyses have traditionally reconstructed event positions by maximizing a complex likelihood function based on PMT hit times. Machine learning presents an interesting alternative to likelihood for reconstruction problems, being able to learn corrections to averaged PDFs, generalise to tasks for which it is difficult to construct a tractable likelihood function, and make predictions much faster than numerical optimization. Complementary approaches to reconstruction can identify shortcomings in likelihood-based methods and provide a fast seed for likelihood optimization. In this poster we explore applications of machine learning to reconstruction tasks in the SNO+ scintillator, presenting neural network structures that can effectively ingest events consisting of an unordered set of PMT hit information. Applied to the position reconstruction of point-like events, we find some performance gains compared to traditional likelihood optimization while evaluating orders of magnitude faster.
Pu-241 is a newly proposed nuclide for studying the nature of neutrinos to complement tritium-based experiments. Pu-241 decays into Am-241 via first-forbidden non-unique beta minus decays with 20.8-keV Q-value and 14.3-year half-life, making it suitable for keV sterile neutrino search as well as active neutrinos mass measurement. MAGNETO-v experiment uses magnetic microcalorimeters in conjunction with quantum magnetometers to acquire the most precise Pu-241 decay spectrum. The experiment’s pure source is provided by Lawrence Livermore National Laboratory. Our first experiment accumulated total 160 million counts above the 3 keV threshold, which is currently the most precise Pu-241 beta decays spectrum. The data yields a |Ue4|2~1e-3 sensitivity to 10-keV neutrinos, which is compatible to the current best limit. More data acquisition is on the way and preliminary analysis results for keV neutrino and active neutrino mass will be presented. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This work was supported by the Laboratory Directed Research and Development program of Lawrence Livermore National Laboratory (23-LW-043).
Current bounds on neutrino Majorana mass are affected by significant uncertainties in the nuclear calculations for neutrinoless double-beta decay. A key issue for a data-driven improvement of the nuclear theory is the actual value of the axial coupling constant g$_A$, which can be investigated through forbidden β-decays. In this contribute, we present the first measurement of 4$^{th}$-forbidden β-decay of In-115 with a cryogenic calorimeter based on Indium Iodide, performed in the framework of the ACCESS project. Exploiting the enhanced spectral shape method for the first time to this isotope, our study accurately determines simultaneously spectral shape, g$_A$, and half-life. The Interacting Shell Model, which best fits our data, indicates a half-life for this decay at $T_{1/2}=(5.26±0.06)\times10^{14}$ yr.
The XENONnT experiment, situated at the INFN Laboratori Nazionali del Gran Sasso, is a dark matter direct detection experiment with a target of 5.9 tonnes of instrumented liquid xenon. The detector aims to detect the O(10)keV signal from a dark matter particle recoil, but it also offers the possibility to measure radioactive decays at higher energies. Our study presents a method to perform a measurement of the energy spectrum of the first-forbidden non-unique beta decay of 214-Bi to the ground state of 214-Po, found in the background radiation originating from the radon decay chain. The interest in this measurement is twofold. Firstly, it provides an internal calibration sample to characterise the detector's response to beta decays. Secondly, it allows comparison of the measured energy spectrum with predictions from nuclear structure model calculations, a challenge itself for these large nuclei.
Discovering neutrinoless double-beta decay ($0\nu\beta\beta$) would be a huge step in understanding the neutrino's nature. The SuperNEMO experiment is designed to search for $0\nu\beta\beta$, using its Demonstrator Module in LSM, Modane, France, at a depth of 4800$\,$m.w.e. Its tracker and segmented, scintillator-based calorimeter enable unambiguous particle identification, time-of-flight and individual energy measurements. SuperNEMO aims to achieve an ultra-low background level of $<10^{-4}\,$events/(keV.kg.yr) in the $0\nu\beta\beta$ ROI. We must therefore understand both internal (within the $\beta\beta$ foil) and external sources of background.
The main external background to the unshielded detector comes from photons produced by $^{208}$Tl, $^{214}$Bi and $^{40}$K decays in the LSM walls. These occasionally interact in the detector, mimicking $\beta\beta$ events. Iron shielding, which will almost eliminate this background, will be installed by summer. This work takes advantage of data taken before shielding installation to measure this photon background. Using SuperNEMO's particle-identification abilities, we present a new measurement of this $\gamma$ flux through multiple channels: by direct $\gamma$ detection; and independently via a measurement of $\beta\beta$-like events generated by $\gamma$. Combining these measurements provides an overall estimate of the $\gamma$ flux at LSM.
Additionally, we have simulated processes anticipated to contribute to the internal background, developing a first version of SuperNEMO's background model. The most significant contribution is expected to be due to contamination of the $\beta\beta$ source foil, where isotopes of $^{208}$Tl, $^{214}$Bi, $^{234m}Pa$ and $^{40}$K can mimic $\beta\beta$ events.
Fully comprehending SuperNEMO's background, combined with its topological reconstruction capabilities, will allow us to search for the $0\nu\beta\beta$ mechanisms and test the possible deviations of the $2\nu\beta\beta$ spectrum from the Standard Model.
Two-neutrino double electron capture (2$\nu$DEC) is a second-order weak interaction process. The half-life of 2$\nu$DEC is directly related to that of neutrino-less double electron capture (0$\nu$DEC) and is of significant importance for revealing the Majorana nature of neutrinos. PandaX-4T is a time projection chamber with 3.7 tons of natural xenon in the active volume, which contains approximately 3.7 kg of Xe-124, a DEC isotope. Using the 655.6 tonne-days of PandaX-4T commissioning Run and the science Run 1 data, we have achieved a precise determination of the 2$\nu$DEC half-life for Xe-124 and searched for possible 0$\nu$DEC signal.
LArIAT is a liquid argon time projection chamber (LArTPC) experiment in a test beam at Fermilab from 2015 to 2017 to understand and characterize interactions of particles in LAr which are commonly observed in neutrino-Ar final-states. Tracks for pions and muons in LArTPCs are difficult to differentiate since both particles exhibit very similar ionization profiles for muon and pion that stop in the TPC. We are exploring unique new particle discrimination capabilities by exploiting information from small, isolated ionization depositions, referred to as "blips", reconstructed near the endpoint of stopping tracks. These blips are formed by gammas emitted when an at-rest pion or muon captures on the argon nucleus. The relatively low beam energy provided by LArIAT makes it uniquely suited for performing this demonstration. In this poster, we present an overview of event candidate selection, blip reconstruction, and background subtraction corresponding to our signal of interest, nuclear captures of pions and muons at rest inside LArIAT's TPC.
The Payload for Ultrahigh Energy Observations is a balloon-borne detector for astrophysical neutrinos with energies in the EeV range. Flying on a long duration balloon over Antarctica, it will measure the radio signals from particle showers that are produced when UHE neutrinos interact within the ice.
A neutrino undergoing charged current interaction will also result in a charged lepton, which can produce additional particle showers. Identifying the characteristic radio emission from these secondary showers would allow us to measure the flavor composition of the UHE neutrino flux.
We will present an outlook for the measurement of the flavor of UHE neutrinos with PUEO, which would give valuable insight into their production processes, let us probe neutrino oscillations at the highest energies, and search for beyond standard model interactions.
Neutrons produced in neutrino interactions tend to represent considerable missing energy, leading to biases in neutrino energy estimates, which in turn can produce biases in measured oscillation parameters. However measuring neutron production in neutrino interactions is challenging. In this poster we present a method for identifying neutrons produced in neutrino interactions in the MicroBooNE liquid argon time projection chamber, leveraging the low thresholds and precise tracking and calorimetry to produce a pure sample of neutrino-induced neutrons with which we can constrain the contributions of neutrons to missing energy. The methods presented would be directly applicable to other liquid argon detectors in the SBN program and DUNE.
Neutrons pose a significant challenge in neutrino experiments where energy reconstruction is critical. The behavior of neutrons is particularly model-dependent because they can take away interaction energy that is largely unseen owing to their non-ionizing nature. Below 20 MeV, many interaction models, like Geant4, employ measurements of final-state particle content to produce accurate neutron interaction topologies. However, there is a lack of data for higher energies, and we must rely on statistical models tuned only to the inclusive interaction cross-section. This can alter the expected visibility of neutrons. NOvA is a long-baseline accelerator neutrino experiment that can leverage its segmented, liquid scintillator-based, high-rate Near Detector to probe neutron interaction models. In this poster, we describe the development and application of an algorithm capable of identifying energy deposits linked to primary neutrons in antineutrino interactions. Additionally, we present the results of a neutron-on-carbon inelastic scattering model as a replacement for Geant4’s intranuclear cascades between 20-O(100) MeV and show an improvement in data-simulation agreement.
The ICARUS detector, situated on the Fermilab beamline as the Far Detector of the SBN (Short Baseline Neutrino) program, is the first large-scale operating LArTPC (Liquid Argon Time Projection Chamber). The mm-scale spatial resolution and precise timing of LArTPC enable voxelized 3D event reconstruction with high precision. A scalable deep-learning (DL)-based event reconstruction framework for LArTPC data has been developed, incorporating suitable choices of sparse tensor convolution and graph neural networks to fully utilize LArTPC's high-resolution imaging capabilities. Michel electrons, which are daughter electrons from the decay-at-rest of cosmic ray muons, have an energy spectrum that is theoretically well understood. The reconstruction of Michel electrons in LArTPC can demonstrate the capability of the system for low-energy electron reconstruction. This poster presents an end-to-end, deep-learning-based approach for Michel electron reconstruction in ICARUS.
Searching for high-energy neutrino emission from Seyfert Galaxies has
become paramount since the IceCube evidence of neutrino emission from NGC 1068. In
this contribution, we present a binned likelihood stacking search for Seyfert Galaxies,
exploiting both KM3NeT/ARCA and ANTARES data. First, we perform a model-
dependent search, testing the state-of-the-art hot corona neutrino modelling for 9 local
Seyfert Galaxies. Furthermore, we consider a model-independent search constructing a
catalogue of 30 Seyfert Galaxies using the B.A.S.S. AGN catalogue. We present the 90%
sensitivity for these scenarios, constraining the emissions of these galaxies.
The MAJORANA DEMONSTRATOR was a neutrinoless double-beta decay ($0\nu\beta\beta$) experiment containing ~44 kg of p-type point contact germanium detectors, of which ~30 kg were enriched to 88% in $^{76}$Ge. The DEMONSTRATOR’s low background rate and excellent energy resolution of 2.52 keV at the $0\nu\beta\beta$ Q-value allowed it to set a lower limit of $8.3 \times 10^{25}$ yrs on the $0\nu\beta\beta$ half-life. Through the use of a multi-layer passive shield, radiopure materials, and analysis-based background rejection techniques, the DEMONSTRATOR achieved one of the lowest background rates of all $0\nu\beta\beta$ experiments at the $0\nu\beta\beta$ Q-value, $6.23 \times 10^{-3}$ cnts/(keV kg yr). However, the observed background rate exhibited significant tension with the assay-based projection of $1.17 \times 10^{-3}$ cnts/(keV kg yr). Spectral fits and supplementary background studies indicate that this discrepancy primarily arose from an excess of events from the $^{232}$Th decay chain, which were non-uniformly distributed between the DEMONSTRATOR’s two modules and which did not originate in a near-detector component. This poster presents the results of background model fits, their implications for the next-generation experiment LEGEND-200, and a measurement of the half-life of two-neutrino double-beta decay, incorporating studies of multiple sources of systematic uncertainty.
This material is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics and Nuclear Physics Programs of the National Science Foundation, and the Sanford Underground Research Facility.
The X-ARAPUCA is the latest iteration of a family of devices capable of detecting single photons from liquid argon scintillation, serving as the building blocks of DUNE's Photo Detection System. Along with the instrumentation for the device, a full physics simulation called ArapucaSim was created that can replicate the observed efficiencies of real devices. This makes it a useful tool for looking for alternatives to both materials and geometries. A bottleneck that results from the simulation of the dichroic filters, which are in charge of trapping the photons inside the X-ARAPUCA's, plagues the simulation's efficiency. Here, we present an alternative model that shifts the computational load to a previous stage, namely the training of a physics informed neural network (PINN). During the ArapucaSim runtime, the PINN's receives the photon's wavelength and incidence angle as input and returns the probabilities of either transmitting, absorbing, or reflecting the photon. This calculation is faster than using a transfer matrix model and at least as fast as interpolating a fine-grained table with the filter's characteristics. The training uses both sources of information, the transfer matrix and measured characteristics, to generate a final algorithm that is less computation intensive during runtime and requires less data to be trained than the interpolation option.
The FASER experiment studies three generations of neutrinos in the unexplored TeV energy region using the Large Hadron Collider at center-of-mass energy of 13.6 TeV.
The FASER detector is located 480 m downstream the ATLAS IP.
The FASER$\nu$ emulsion detector, a component of FASER, consists of 730 layers of emulsion films and tungsten plates, with a target mass of 1.1 tons.
Thanks to the high spatial resolution of the emulsion detector, FASER$\nu$ can detect all neutrino flavors and measure differential cross-sections.
The objective of this work presented here is to develop a method to reconstruct momenta of high-energy charged particles in the FASER$\nu$ detector by means of the multiple Coulomb scattering.
In this poster, we will report on the evaluation results from Monte Carlo simulations, the status of irradiation and analysis in a test beam experiment in summer 2023, and an application of the method to FASER$\nu$'s 2022 data.
The Large Enriched Germanium Experiment for Neutrinoless $\beta \beta$ Decay (LEGEND) is an experimental program dedicated to the search for the neutrinoless $\beta \beta$ decay of $^{76}$Ge. The experiment is being designed to reach a half-life sensitivity of $10^{28}$ yr in the next experimental phase, LEGEND-1000, which requires a background rate of $10^{-5}$ cts/(keV$\cdot$kg$\cdot$yr). Attaining such rare event rate requires a number of measures to reduce background due to more frequent phenomena. For the current experimental phase, LEGEND-200, a muon veto system uses a water-based Cherenkov detector to actively reduce background. It uses photomultiplier tubes as light detectors in a water tank covered with a reflective foil to increase the light collection efficiency inside the water volume. In this poster we present the operating principle and latest data analysis of the current muon veto and discuss plans for its future developments for LEGEND-1000.
This work is supported by the U.S. DOE and the NSF, the LANL, ORNL and LBNL LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Russian RFBR; the Canadian NSERC and CFI; the LNGS, SNOLAB, and SURF facilities.
Knowledge of the neutrino flux is necessary to precisely measure neutrino oscillation parameters with accelerator-generated neutrino beams. Hadron production is a dominant source of neutrino flux uncertainty in long-baseline neutrino experiments, such as NOvA, T2K, and DUNE. These uncertainties are reduced by precisely measuring hadron-nucleus interactions in the target materials used to create neutrino beamlines. The NA61/SHINE experiment at CERN provides many hadronic production measurements for this purpose. This poster will discuss these measurements in thin and replica targets that apply to the neutrino oscillation programs at Fermilab and J-PARC.
A simulation of the neutrino beam for the upcoming Hyper-Kamiokande (Hyper-K) experiment is essential for predicting neutrino fluxes accurately at the near and far detectors, which is crucial for measuring various neutrino oscillation parameters such as mixing angles, mass differences and the CP-violating phase. G4Jnubeam is a new beam simulation software based on the GEANT4 package currently under development for Hyper-K. It has been designed to simulate all aspects of neutrino production including proton beam simulation, decays of hadrons and muons into neutrinos, and ultimately the neutrino incident fluxes at both the near and far detectors. Additionally, G4Jnubeam is used to investigate alternative target configurations for the Hyper-K design that can lead to reduced wrong-sign contaminations in neutrino beam flux calculations. Some simulation results for validation against external hadron production measurements from the NA61/SHINE experiment, neutrino flux predictions for the Hyper-K near and far detectors, and the effects of having a longer and denser target on the neutrino beam production are presented.
The Deep Underground neutrino experiment (DUNE), consisting of near (DUNE-ND) and far (DUNE-FD) detectors, is a long-baseline experiment that is designed to measure neutrino oscillations, as well as searches beyond the standard model. The DUNE-FD will operate with a total volume of 70 kiloton liquid argon and will be situated at Sanford Underground Research Facility (SURF) in South Dakota. The DUNE-ND will be placed close to the neutrino source and measure an un-oscillated neutrino beam for precise measurement of oscillation parameters. I will present the impact of using model systematics on the neutrino energy scale measurements in DUNE using advanced computing at Argonne.
The field of neutrino oscillation study is full of unique and insightful experiments, and global fits can be conducted to study their results in a unified and coherent approach, exploiting the strengths of the different experiments. For the success of a global study, factors such as experiment modelling, parameter space exploration, and statistical interpretation are of vital importance.
In this work, we present preliminary results from the first three-flavour neutrino global fit performed with the Global and Modular BSM Inference Tool (GAMBIT). GAMBIT is an open-source global fitting software package for studying generic particle and astronomical physics models. Its modular design allows easy implementation of likelihood functions and models. The built-in scanners also provide robust and efficient statistical sampling techniques.
Our neutrino global fit includes results from eight neutrino oscillation experiments of different types, including solar, reactor, atmospheric, and long-baseline accelerator. The fit also uses only publicly accessible experiment data and information, adhering to the open-source policy. In the fit, each experiment is represented by a set of likelihood functions. Realistic and physics-motivated systematic models along with sets of nuisance parameters are introduced to account for systematic uncertainties for the detector effects and the neutrino fluxes, to name a few. For a given combination of neutrino oscillation parameters and nuisance parameters, a combined likelihood can be calculated. A self-adaptive differential evolution sampling algorithm is utilised to explore the vast parameter space and search for the best-fit point. Rigorous and modern statistical methods are adopted to interpret the sampling result, maximising the accuracy of the global fit.
Liquid Argon Time Projection Chamber (LArTPC) detectors offer impressive charged particle imaging capability with high spatial resolution. Precise event reconstruction procedures are mandatory in order to fully exploit the potential of this technology.
The ICARUS collaboration employed the 760-ton T600 detector in a successful three-year physics run at the underground LNGS laboratory. A sensitive search was performed for LSND-like anomalous $\nu_e$ appearance in the CNGS beam, contributing to the constraints on the allowed neutrino oscillation parameters within a narrow region around 1 e$V^2$. Following a significant overhaul at CERN, the T600 detector was relocated to Fermilab to begin to operate as the far detector in the Short-Baseline Neutrino Program (SBN). ICARUS has entered the physics run phase and is presently collecting large statistical samples for its proposed physics analysis program.
This poster will present ICARUS event selection along with the currently employed reconstruction and analysis algorithms. Initial studies have been conducted with a well defined sample of $\nu_\mu$ $CC$ quasi elastic interactions, demonstrating promising and robust results of fully reconstructed neutrino events. Detailed investigations are undergoing to develop an efficient and automatic selection towards a final oscillation analysis, the status of which will also be reported here.
We discuss a left-right (L-R) symmetric model with
the double seesaw mechanism at the TeV scale generating Majorana
masses for the active left-handed (LH) flavour neutrinos
$\nu_{\alpha L}$ and the heavy right-handed (RH) neutrinos $N_{\beta R}$, $\alpha,\beta = e,\mu,\tau$, which in turn mediate lepton number violating processes, including neutrinoless double beta decay.
The Higgs sector is composed of two Higgs doublets $H_L$, $H_R$ and a bi-doublet $\Phi$. The fermion sector has
the usual for the L-R symmetric models quarks and leptons, along with three $SU(2)$ singlet fermion $S_{\gamma L}$. The choice of bare Majorana mass term for these sterile fermions induces large Majorana masses for the heavy RH neutrinos leading to two sets of heavy Majorana particles $N_j$ and $S_k$, $j,k=1,2,3$, with masses
$m_{N_j} \ll m_{S_k}$. Working with a specific version of the model in which the $\nu_{\alpha L} - N_{\beta R}$ and the $N_{\beta R} - S_{\gamma L}$ Dirac mass terms are diagonal, and assuming that $m_{N_j} \sim (1 - 1000)$ GeV and ${\rm max}(m_{S_k}) \sim (1 - 10)$ TeV, $m_{N_j} \ll m_{S_k}$, we study in detail the new ``non-standard'' contributions to the $0\nu\beta\beta$ decay amplitude and half-life
arising due to the exchange of virtual $N_j$ and $S_k$.
We find that in both cases of NO and IO light neutrino mass spectra, these contributions are strongly enhanced and are dominant at relatively small values of the lightest neutrino mass $m_{1(3)} \sim (10^{-4} - 10^{-2})$ eV over the light Majorana neutrino exchange contribution.
In large part of the parameter space, the predictions of the model for the $0\nu\beta\beta$ decay generalised effective Majorana
mass and half-life are within the sensitivity range of the
planned next generation of neutrinoless double beta decay
experiments LEGEND-200 (LEGEND-1000), nEXO, KamlAND-Zen-II, CUPID, NEXT-HD.
The Cryogenic Underground Observatory for Rare Events (CUORE) is a ton scale experimental search for 0$\nu\beta\beta$ decay on ${}^{130}$Te. The CUORE detector consists of 988 TeO$_2$ crystals operating as cryogenic bolometers at the Gran Sasso National Laboratory (LNGS) in Italy. While simulations suggest that about 11\% of 0$\nu\beta\beta$ decay events deposit energy in more than one crystal, the standard CUORE analysis considers only single-site events. In this talk we present the preliminary results of the search using dual-site events in CUORE, including the analysis techniques used to reconstruct the energy, suppress backgrounds, and estimate future sensitivity.
The nEXO experiment will search for neutrinoless double beta (0$\nu\beta\beta$) decay using a 5-tonne liquid xenon (LXe) time projection chamber (TPC), enriched to 90% in Xe136, with a projected half-life sensitivity $>$ 10$^{28}$ years after 10 years of lifetime. The observation of lepton number non-conserving 0$\nu\beta\beta$ decay would imply new physics and require neutrinos to be Majorana fermions. With a general overview of the nEXO experiment, we present tests carried out in LXe at Stanford of prototype cryogenic application specific integrated circuits (ASICs) for the readout of ionization charge specifically developed for nEXO by SLAC. This solution is chosen to meet low noise requirements due to reduced capacitance and to allow for high density channels without large masses of radioactive cabling. Additionally, we will share details of a 64kg LXe TPC, able to accommodate a 4-tile charge readout module (each tile is 10cm x 10cm) is under construction to investigate cross-talk between tiles and its impact on energy resolution. Finally, we will present on a LXe purity monitor, designed and built to measure the concentration of electronegative species emanated by materials considered for nEXO.
This work investigates the physics potential of hypothetical large-scale detectors observing the interactions of neutrinos produced in proton-proton collisions at the LHC. We focus on the LHCb interaction point, as the forward neutrino flux from this location passes through Lake Geneva before exiting the Earth's surface. This offers two interesting possibilities: (1) a long pipe-like detector deployed within Lake Geneva, and (2) a large panel-based detector deployed on the Earth's surface. The former can leverage the large active volume enabled by the lake environment to collect a large dataset of all-flavor neutrino interactions within the detector, while the latter can leverage the long range of TeV-scale muons to collect a large dataset of muon neutrino interactions in the surrounding bedrock. One could also perform a coincidence measurement of muon neutrinos interacting in the lake-based detector and producing muons that are then observed in the surface-based detector. We estimate the event rates using a custom Monte Carlo simulation and show that these detectors can pin down the charm hadron contribution to the forward neutrino flux. Such a measurement would significantly constrain existing uncertainties on the prompt atmospheric neutrino flux, which is an important and poorly understood background to astrophysical neutrino searches at current and next-generation neutrino telescopes.
We present the method of determination of neutron capture cross section on Carbon with 3158 days of operation of Daya Bay reactor antineutrino experiment through the inverse beta decay reaction. The detection process involves the annihilation of a positron followed by a thermalized neutron capture event. In Daya Bay experiment, three predominant forms of neutron capture events emerge: neutron-hydrogen, neutron-gadolinium, and neutron-carbon interactions. In this study we use hydrogen and gadolinium as comparative elements to determine the cross section of $^{12}C(n,\sigma)^{13}C$ by neutrons arising from inverse beta decay.
The Deep Underground Neutrino Experiment (DUNE) wants to advance our understanding of neutrinos with remarkable precision. The main sources of detector systematic uncertainties are limitations of calibration and modeling of particles in the detector. Neutrons especially can account for up to 20% of the energy response uncertainty. In order to facilitate more accurate neutrino measurements in DUNE’s far detector by addressing this uncertainty, we plan to study these neutrons with the DUNE near detector. Our approach involves identifying neutrons by associating disjointed proton tracks with a neutrino interaction vertex. The 2x2 demonstrator for the DUNE near detector, positioned at Fermilab's NuMI beamline, provides an ideal platform for developing these neutron studies. Featuring eight optically segmented volumes, the 2x2 configuration effectively mitigates light-pileup issues, enabling determination of the neutron time of flight and therefore the kinetic energy. In this poster, we discuss the methodologies and the preliminary findings of our neutron studies in the 2x2 demonstrator.
T2K (Tokai to Kamioka) is a Japan-based long-baseline neutrino oscillation experiment designed to measure (anti)neutrino flavor oscillations. A muon (anti-)neutrino beam peaked around 0.6 GeV is produced in Tokai and directed toward the water Cherenkov far detector Super-Kamiokande (SK) located at 295 km. The ND280 is used to characterise the neutrino beam before the oscillation, and its data are used to tune the neutrino flux and cross-section models which are then used to predict the expected number of neutrinos at SK. In this poster, I will present the status of an updated analysis of the near detector (ND280) data, counting numerous improvements as a new selection ensuring to cover a wider phase space of the outgoing muons, with a better characterization of the low momentum transfer regions, improved events reconstruction, near-detector modeling, and cross-section modeling. GUNDAM, which stands for Generic fitter for Upgraded Near Detector Analysis Method, is a new tool developed to measure the neutrino flux and cross-section at the T2K near detector. It consists of a suite of applications interfaced to a flexible and highly optimized code structure. I will discuss briefly its features and performance, and then its main results.
The Super-Kamiokande (SK) experiment has the world's leading sensitivity to the astrophysical electron anti-neutrinos up to a few tens MeV, such like supernova originating neutrinos. In 2020, SK was upgraded to enhance its neutron capture signal by loading gadolinium, termed as the SK-Gd phase. Since 2022, more Gd has been loaded to achieve about 75% of neutron captures on Gd. Thanks to this, we continue reducing muon spallation backgrounds while increasing signal efficiency. One of the remaining dominant backgrounds are also atmospheric neutral-current quasi-elastic (NCQE) neutrino interactions. In this poster, we present a new method to reduce these NCQE events by up to a further factor of 10 as well as a dedicated neutron detection neural network to reduce 10^4 of muon spallation events. Finally, we show the results for the upper limits on the electron anti-neutrino flux that we can set with these improvements in the SK-Gd era
NOvA is a long-baseline neutrino experiment at Fermilab that studies neutrino oscillations via electron neutrino appearance and muon neutrino disappearance. The oscillation measurements compare the Far Detector data to an oscillated prediction informed by the Near Detector (ND) data. This ND-informed prediction is produced from the neutrino generator GENIE, which provides NOvA with a set of interaction uncertainties. However, this coverage does not account for all interaction uncertainties relevant for NOvA, in particular for resonance production (RES) and deep inelastic scattering (DIS) processes, which comprise a substantial portion of NOvA's interactions. Here we introduce six new cross section uncertainties that affect RES and DIS interactions, which represent degrees of freedom not available in the previous NOvA model. After careful studying of their impact, we incorporate them to the NOvA cross-section model. We show the impact of these new uncertainties on various reconstructed quantities.
In 2023, the MicroBooNE experiment published its first constraints on light sterile neutrino oscillations using neutrinos from the on-axis Booster Neutrino Beam (BNB). A limitation of this first result came from the cancellation between electron neutrino disappearance and muon neutrino to electron neutrino appearance oscillations leading to a degeneracy in the extracted oscillation fit parameters. A new search for a sterile neutrino is being carried out simultaneously using neutrinos from both the on-axis BNB at a baseline of ~470 m with mean neutrino energy at 800 MeV and the off-axis Neutrino from the Main Injector (NuMI) beam at a baseline of ~680 m with neutrinos up to a few GeV. MicroBooNE’s two beam measurement allows to break this degeneracy leveraging the different intrinsic electron neutrino to muon neutrino ratios in BNB (~0.5%) and NuMI (~5%). This significantly expands the experiment’s sensitivity, allowing to probe parameter space for test the sterile neutrino hypothesis compatible with short baseline anomalies from the LSND, Neutrino-4, Gallium, and BEST experiments. In this poster, the status of this analysis will be reported.
The oscillation of neutrinos has been measured in various channels since its experimental confirmation in 1998. However, there are only few observations of the tau neutrino appearance with large uncertainties. Better constraints on $|U_{\tau3}|^2$ are needed to probe the unitarity of the PMNS matrix U in the third mass eigenstate column $\left| U_{e3} \right|^2 + \left| U_{\mu 3} \right|^2 + \left| U_{\tau 3} \right|^2 = 1$. KM3NeT consist of two water-Cherenkov neutrino telescopes being deployed in the Mediterranean sea, near the coasts of France and Italy. In particular KM3NeT/ORCA, is optimised to measure the neutrino oscillation properties. Thanks to its compact geometrical layout it is sensitive to atmospheric neutrinos with energies as low as 3 GeV adequate to perform non unitarity tests. This contribution will report on the new results of testing the non unitarity of the neutrino mixing, obtained using an early six-lines configuration of the ORCA detector (ORCA6), with data recorded in 2020 and 2021.
Neutrino experiments are set to probe some of the most important open questions in physics, from CP violation and the nature of dark matter. The technology of choice for many of these experiments is the liquid argon time projection chamber (LArTPC). In current LArTPC experiments, reconstruction performance often represents a limiting factor for the sensitivity. New developments are therefore needed to unlock the full potential of LArTPC experiments.
NuGraph2 is a state of the art Graph Neural Network for reconstruction of data in LArTPC experiments. NuGraph2 utilizes a heterogeneous graph structure, with separate subgraphs of 2D nodes (hits in each plane) connected across planes via 3D nodes (space points). The model provides a consistent description of the neutrino interaction across all planes. NuGraph2 is a multi-purpose network, with a common message-passing attention engine connected to multiple decoders with different classification or regression tasks. These include the classification of detector hits according to the particle type that produced them (semantic segmentation) and the separation of hits from the neutrino interaction from hits due to noise or cosmic-ray background. Additional decoders are being developed, performing tasks such as the regression of the neutrino interaction vertex position.
Performance results will be presented based on publicly available samples from MicroBooNE. These include both physics performance metrics, achieving 95% accuracy for semantic segmentation and 98% classification of neutrino hits, as well as computational metrics for training and for inference on CPU or GPU. The status of the NuGraph integration in the LArSoft software framework will be presented, as well as initial studies about model interpretability and injection of domain knowledge.
The highly detailed images produced by liquid argon time projection chamber (LArTPC) technology hold the promise of an unprecedented window into neutrino interactions; however, traditional reconstruction techniques struggle to efficiently use all available information. This is especially true for complicated interactions produced by tau neutrinos, which are typically large, consist of many tracks, and differ from other interactions largely by subtle angular differences.
NuGraph2, the Exa.TrkX Graph Neural Network (GNN) for reconstruction of LArTPC data is a message-passing attention network over a heterogeneous graph structure, with separate subgraphs of 2D nodes (hits in each plane) connected across planes via 3D nodes (space points). The model provides a consistent description of the neutrino interaction across all planes. The GNN performed a semantic segmentation task, classifying detector hits according to the particle type that produced them, achieving ~95% accuracy when integrated over all particle classes.
Based on this success, we are building a new network, NuGraph3, which will generalize NuGraph2's structure to a hierarchical message-passing attention network. The lowest layer will consist of the same subgraphs of 2D nodes that NuGraph2 operates on. Higher layers will be dynamically generated through a learned metric space embedding. This will allow the network to build higher level representations out of low level hits. After iterative refinement, the hierarchical structure will reflect a particle tree reconstruction of each event. This hierarchical structure also provides a natural way to construct event level features for use in reconstructing quantities like vertex position and neutrino interaction classification. We will present preliminary work building particle clusters, and compare semantic segmentation results with and without hierarchical message passing.
NvDEx is a new Se-based TPC detector that will look for neutrinoless double beta decay. It will be placed in China JingPing Underground Laboratory, where the large rock overburden (2.4 km) will suppress significantly the cosmogenic background. Moreover, the high Q-value of $^{82}$Se, 2.996 MeV, will place the ROI well above most of the environmental background. As a result, it will be possible to achieve an incredibly low background environment, which ensures excellent perspectives for scalability.
NvDEx-100, the first phase of the experiment using 100 kg of SeF$_6$ gas, is currently under construction and planned to start taking data in 2026. I will present the current status of the experiment and the perspectives for future developments.
One of the main challenges to overcome is the high electronegativity of SeF$_6$, which means that the electrons will recombine very quickly and the particles traveling toward the readout plane will be negative ions. A new kind of sensor, Topmetal-S, has been developed: it will allow us to read out the drifted charge and reconstruct the energy of the event with great precision even without physical amplification like electron avalanche.
Super-Kamiokande is a large underground water Cherenkov detector for neutrino physics and nucleon decay search in Kamioka, Japan. We upgraded its detector with gadolinium (Gd) in 2020 (SK-Gd) to improve electron antineutrino ($\bar{\nu}_{\text{e}}$) identification. The higher energy yield from neutron capture of Gd enables the SK trigger system to apply to a lower energy region in $\bar{\nu}_{\text{e}}$ search than that in the pure water phase where the previous search had a 9 MeV energy threshold.
Many scintillator experiments have measured reactor antineutrinos well, especially in the KamLAND detector in the long baseline over 100 km. No large-scale water Cherenkov detector succeeded in the long-baseline measurements except for the evidence in the SNO+ experiment.
We conducted electron antineutrino analysis from 4 MeV $\bar{\nu}_{\text{e}}$ energy threshold via inverse beta decay in the first Gd phase (0.01% concentration), $536 \times 22.5~\text{days} \cdot \text{kt}$ exposure from 2020 summer to 2022 summer, and observed reactor neutrino. In this poster, we will show the result of reactor neutrino analysis in the first Gd phase (0.01%) and its status in the second Gd phase (0.03%). In addition, we will discuss the application of reactor neutrino measurement in SK-Gd.
P-ONE (Pacific Ocean Neutrino Experiment) is a future cubic-kilometre scale water Cherenkov neutrino telescope that will be located in the Pacific Ocean off the coast of Canada. P-ONE has a broad program including various topics in neutrino astronomy, oceanography and climate monitoring. The detector itself will be made of 70 lines consisting of 20 P-OMs (P-ONE optical modules) and connected to the existing infrastructure built by Ocean Networks Canada (ONC). The P-OM is a light detection unit that consists of 16 PMTs (Photomultiplier tubes) encased in a glass pressure housing. The first line of the detector is currently under development and planned to be deployed in 2025. Characterization of P-OM is a crucial part for estimating the performance and sensitivity of the future detector as a whole. A dedicated automatic calibration setup is currently under development at the Technical University of Munich. This setup will automatically calibrate the assembled optical modules for the usage anticipated in the deep sea, such as detection of neutrinos or bioluminescence in the Ocean. This contribution discusses the optical module features and the setup preliminary performance, planned operations, as well as some initial implementations of the measurements into the simulation toolkit.
Finding evidence of neutrinoless double beta decay would reveal the Majorana nature of the neutrino and give insight into the origins of the matter-antimatter asymmetry in the universe, the smallness of neutrino mass, and the symmetry structure of the Standard Model. The NEXT collaboration is developing a sequence of high pressure xenon gas time projection chambers with the aim of creating a ton-scale, very low background neutrinoless double beta decay search. NEXT-CRAB (Camera Readout And Barium tagging) demonstrates new designs that enable scaling NEXT beyond the ton scale and ultimately provide a background free signal, enabling measurements that probe the normal neutrino mass ordering. To do this we are employing several novel techniques, one of which is using direct VUV imaging of the electroluminescence with a TimePix3 camera and image intensifier. This poster will present the latest results of the first high resolution 3 dimensional tracks with an optical xenon gas time projection chamber where all the readout devices are outside the vessel. This technique improves radiopurity, reduces heat load, is easily scalable and opens the cathode plane for incorporation of barium tagging, a novel technique developed to distinguish each time the daughter nucleus of double beta decay is within the detector volume.
The discovery of neutrinoless double beta decay ($0\nu \beta \beta$) would definitively prove both that lepton number is not a fundamental symmetry in nature and that neutrinos are their own antiparticles. Furthermore, being a purely matter-creating process, it would be pivotal for our best theories of the matter-antimatter asymmetry in our universe. LEGEND (Large Enriched Germanium Experiment for Neutrinoless double beta Decay) is a multiphase program to search for ($0\nu \beta \beta$) in ${}^{76}Ge$, the first phase of which, LEGEND-200, is currently running at LNGS in Italy with an eventual discovery sensitivity at a half-life of $10^{27}$ years. To reach this sensitivity LEGEND has several layers of active background mitigation to ensure backgrounds are as low as possible namely: a multiplicity cut for events in multiple detectors, the Liquid Argon coincidence cut and Pulse Shape Discrimination in the individual detectors. Legend has been in stable data taking now for more than 1 year with over 100 kg of Ge detectors and here the overall performance of the active background suppression in terms of the background index will be presented alongside the unblinding strategy and methodology.
This work is supported by the U.S. DOE and the NSF, the LANL, ORNL and LBNL LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Russian RFBR; the Canadian NSERC and CFI; the LNGS, SNOLAB, and SURF facilities.
In the framework of Physics Beyond Colliders (PBC) initiative at CERN, a concept for a short-baseline neutrino beamline is currently being studied. Particularly, the ENUBET and NuTag collaborations that previously designed different versions of short and long baseline monitored and tagged neutrino beams are now collaborating towards a common design and conceptual feasibility study. Within the scope of the Conventional Beams working group at CERN, this short-baseline design, designated "SBL Neutrino Beamline (SBL)", provides, if approved, the unique opportunity to perform a high-precision (O(1%)) measurement of the electron neutrino cross-section in the low-GeV neutrino energy range.
A key parameter for the operation and ultimately the feasibility of such a beamline is its efficiency, i.e., the optimization of the number of required protons on target to achieve the goal of a cumulative flux of $10^{4}$ electron neutrinos in a near detector.
In this contribution, the current design for the short baseline as well as a conceptual study of an alternative long baseline is presented. In addition, a state-of-the art optimization framework is presented. The optimized design for the short baseline features significant performance improvements over the previously studied alternative.
The DUNE Far Detector will consist of four Liquid Argon TPC modules. One module will use the newly proposed Vertical Drift Technology, where the anode is made of 2 stacked drilled PCBs. A large scale prototype has been assembled at the CERN Neutrino Platform (ProtoDUNE-VD) and will start collecting cosmic data in fall 2024.
The ProtoDUNE-VD is made of 4 anode modules, which have all been individually tested in a dedicated fully instrumented small-scale cryostat. This poster will show the performances of the 4 anodes in terms of noise and calorimetric response. Two anode assembly procedures have been tested and their performances will be compared. Finally, charge and light signals were matched and first results will be presented in the poster.
The Deep Underground Neutrino Experiment (DUNE) is a next generation long baseline neutrino experiment aiming to provide insight towards the main outstanding questions in neutrino physics. It will operate four enormous far detector modules, placed 1300 km from the baseline 1.5 km underground.
The second of these far detectors will consist of a Liquid Argon Time Projection Chamber (LArTPC), as well as a Photo-Detection (PD) System that will provide complementary information for timing, position reconstruction and calorimetry. The work presented here concerns the PD system, presenting the design of its readout electronics. To enhance the coverage of the PD system and improve its uniformity, detectors will be positioned on the high voltage surface of the cathode. A "Signal-over-Fiber" concept was thus developed, to transmit the signals using only non-conductive materials. It is complemented by a "Power-over-Fiber" technology that allows to power these electronics using powerful lasers. This poster presents the design and the characterisation of these electronics, as well as the results of the integration tests carried out at the CERN Neutrino Platform.
The nEXO experiment, a pioneering initiative aimed at searching for the elusive neutrinoless double beta decay of $^{136}$Xe, sets an ambitious half-life sensitivity target exceeding $10^{28}$ years. The project utilizes a 5-tonne liquid xenon (LXe) Time Projection Chamber (TPC), right-cylindrical with a diameter of $1.3$ m. Achieving precise calibration of the detector's ionization and scintillation responses is paramount, necessitating innovative strategies to overcome the LXe's inherent self-shielding capability, which complicates the use of external radioactive sources. Strategic injection of $^{220}$Rn and $^{127}$Xe isotopes into the xenon is planned to reach the innermost volume of the detector. Yet, to enhance calibration precision and to mitigate potential risks, University of Massachusetts Amherst leads the development of a method for in-situ generation and monitoring of drift electrons, and the light response of silicon photomultipliers within LXe. This novel approach is demonstrated using a small-scale, LXe dual grid ionization chamber, looking forward to enabling continuous monitoring of ionization electron lifetimes. Our poster presents the status, including preliminary results of this effort, highlighting the possible integration of gold photocathodes into the nEXO framework.
ESSnuSB (European Spallation Source neutrino Super-beam) is an upcoming accelerator-based neutrino oscillation experiment which aims to measure the leptonic CP violation phase by measuring at the second oscillation maximum. The neutrinos produced in the ESS will be detected at a distance of 360 km using half megaton underground water Cherenkov neutrino detector. Additionally, there is a proposal to build a low energy muon storage ring (LEnuSTORM) similar to the nuSTORM project and to build a low energy monitored neutrino beam line (LEMNB), inspired by the ENUBET project. These neutrinos will be detected at several near detectors located at the ESS site. In this poster, I will present the results of the physics scenarios which can be studied in this ESSnuSB+ setup. These physics scenarios can be: (i) beam based scenarios at the far and near detectors, for example, study of neutrino oscillations in standard three flavour scenario and several new physics scenarios (including sterile neutrino, non-standard interaction, quantum decoherence, neutrino decay etc) and (ii) non-beam based scenarios at the far detector, for example study of atmospheric neutrinos and supernova neutrinos. My focus in this poster will be to present results related to beam based physics results in the standard scenario and the results for supernova neutrinos.
In the neutrinoless double beta decay search using a low-temperature detector technique such as AMoRE, one of the major background sources at the energy range of interest is an accidental coincidence of two background signals at one crystal detector, so-called pile-up. While a large mass$\cdot$time exposure is the key parameter of the experimental sensitivity, the pile-up event rate ultimately limits the crystal size, which determines the number of detector modules and data acquisition channels. For a typical AMoRE crystal detector with a cylindrical shape of 6 cm in both diameter and height and 2-3 millisecond signal rise-time, the pile-up event rate in AMoRE-II with ~360 detector modules can be suppressed down below 3$\times10^{-5}$ counts/keV/kg/year level using multivariate analysis of pulse shape parameters.
NOvA is a long-baseline neutrino oscillation experiment with two functionally identical detectors, a Near Detector (ND) at Fermilab, placed 1km from the neutrino source, and a Far Detector (FD) located 810 km away from the ND in Minnesota. NOvA’s primary physics goals are to measure the neutrino oscillation parameters $\theta_{23}$ and $\Delta m^2_{32}$ with high precision, determine the neutrino mass hierarchy, and constrain the value of $\delta_{CP}$, primarily via the study of muon neutrino to electron neutrino oscillation. Furthermore, NOvA is also able to probe sterile neutrino oscillations via the study of neutrino events depletion in neutral current interactions between the Near and Far Detector. Extracting values for oscillation parameters from fits to data usually relies on treating systematic uncertainties as nuisance parameters, which suffers from poor scalability as the number of uncertainties becomes larger. In this poster, we present PISCES (Parameter Inference with Systematic Covariance and Exact Statistics), a novel method that circumvents this scalability problem by encoding systematic uncertainties into a covariance matrix. PISCES utilizes a nested minimization in which optimal systematic pulls are first computed using the covariance matrix, then the oscillation parameters are profiled with a fitter. As it solves for each oscillation channel within each sample independently, PISCES also has the advantage of supporting complex fits, such as a joint Near and Far detector fit. Moreover, it treats statistical uncertainties with a Poisson Likelihood term, so it is ideal for the inclusion of low-statistic samples in the fits. This method has been used to produce the most recent results from NOvA’s search for sterile neutrinos, presented in this poster. The PISCES two-detector fit can also be applied to the NOvA three-flavor analysis where extensive robustness tests of the method have been carried out and the resulting performance is presently shown.
Although the standard 3-flavor framework has been firmly established and
the phenomenon of neutrino oscillations is very well understood within this
framework, there are anomalies in the experimental data which cannot be ac-
commodated in this scenario. One of the explanations for these anomalies is
the extension of the 3-flavor paradigm with an additional sterile neutrino.
Although it is theoretically very well motivated to extend SM with a such new
SU(2) singlet, its existence is yet to be established experimentally.
NINJA experiment is designed to measure neutrino-nucleus cross-sections using
nuclear emulsion films and a high-intensity neutrino beam from J-PARC. This
short-baseline experiment allows to explore different physics cases apart from
the neutrino-nucleus cross-section measurement. One of them is the search for
the sterile neutrino at the eV scale. In this poster, I will explore sensitivity of
the NINJA experiment in order to put constraints on sterile neutrino parame-
ters in the future runs. In this context, I will show the effect of different flux
options probed at the different target materials.
ZICOS is a one of future experiments for neutrinoless double beta decay using $^{96}$Zr nuclei. In order to achieve sensitivity over $10^{27}$ years, ZICOS will use tons of $^{96}$Zr, and need to remove $^{208}$Tl background events as observed by KamLAND-Zen one order of magnitude. For this purpose, we have developed new technique to distinguish the signal and background using a topology of Cherenkov light. In order to demonstrate this method, we are planning to observe about 100 $^{96}$Zr two neutrino emission double beta decay events per year using 1 little of ZICOS liquid scintillator containing 0.4 g of $^{96}$Zr filled in 2$\nu$-ZICOS detector. Here, we will report a present status of this experiment which will start the observation in this summer.
During a core-collapse supernova, a large fraction of neutrinos come out from the proto-neutron star. Some of these neutrinos pair annihilate to produce an electron-positron pair. This process in the fireball is the main source of large GRB energy. In this poster, I will discuss interesting constraints on $Z^\prime$ couplings obtained from GRB observations. I will also discuss that the active-sterile neutrino oscillation in the ultralight dark matter background can also resolve the long-standing problems for the pulsar kick.
Neutrino-less double-beta (0νββ) decay is a rare nuclear process with profound implications for verifying the Majorana nature of neutrinos and determining their masses. The Majorana nature of neutrinos is crucial for understanding neutrino properties and the origin of the matter-dominant universe.
The KamLAND-Zen experiment, located at the Kamioka underground laboratory in Japan, has been at the forefront of the search for 0νββ decays for more than a decade. The experiment started a search for 0νββ decay of xenon-136 nuclei in 2011 (KamLAND-Zen 400), which was upgraded in 2019 by doubling the number of xenon nuclei and a tenfold reduction in uranium and thorium contamination (KamLAND-Zen 800). In addition, many new analytical technics has been developed, including particle identification with neural network. A combined analysis of the KamLAND-Zen 400 and 800 dataset has provided the world's most stringent limits on the effective Majorana neutrino mass of 36-156 meV with different nuclear matrix elements. This result establishes KamLAND-Zen as a pioneering effort in the global pursuit to unravel the fundamental properties of the neutrino.
The KamLAND-Zen collaboration has taken the next step forward: The upcoming phase of KamLAND-Zen, KamLAND2-Zen, will employ a new high light-yield liquid scintillator, light collecting mirror, high quantum efficiency photomultipliers and new readout electronics to increase sensitivity.
This poster presentation aims to outline the current status and future directions of research and development for the KamLAND2-Zen experiment.
Ultra-High Energy (UHE) neutrinos, those with energy greater than 100 PeV, have yet to be observed but are theorized to originate from astrophysical and cosmogenic sources. The Askaryan Radio Array (ARA) is a UHE neutrino observatory located at the South Pole that was built to discover such UHE neutrinos. ARA is composed of 5 stations that are each made up of vertically and horizontally polarized radio antennas installed up to 190 meters deep in the Antarctic glacier. The fifth of these stations has a phased array component that allows for lower threshold observations. Previous ARA measurements have demonstrated the ability to reject anthropogenic backgrounds and set leading limits on the UHE neutrino flux below ~20 EeV as measured by radio experiments thus far. The ARA stations have accumulated more than 30 station-years worth of data, of which only a fraction has been analyzed and published. A concerted effort to analyze the full livetime of data in all of the ARA stations is currently underway, with significant effort from multiple institutions of the collaboration. The search through this data set builds on previous analyses and aims to coordinate analysis strategies across stations to optimize for discovery. This poster summarizes the ARA collaboration’s presently ongoing neutrino search of all data taken from 2013 through 2021, which will discover the first UHE neutrino or set the strongest radio limit on their flux in the 1-100 EeV energy range.
The Daya Bay experiment has accumulated the world’s largest reactor antineutrino sample, which enables several critical precise measurements. Based on about 4.7 million inverse beta decay (IBD) candidates recorded at the Daya Bay near detectors throughout their entire operational lifespan, we present the latest measurements of reactor antineutrino flux and spectrum in this poster. Specifically, the rate analysis of the reactor antineutrino flux offers precise measurements of the average IBD yield, the fuel-dependent variation in the IBD yield, and the isotopic IBD yields of $^{235}U$ and $^{239}Pu$. Concerning the reactor antineutrino energy spectrum, we report the precise measurements of the overall IBD yield spectrum and the isotopic spectra of $^{235}U$ and $^{239}Pu$. Furthermore, the reactor antineutrino energy spectra are unfolded from observed reconstructed energy to neutrino energy in order to facilitate the comparison and prediction for other experiments.
XENONnT is a state-of-the-art dark matter and neutrinos experiment hosted at the Laboratori Nationali del Gran Sasso (LNGS), in Italy. In its core, the experiment runs a time projection chamber (TPC) with an active target of 5.9 t of the liquid xenon at very low background conditions and keV-level energy threshold.
Although primarily developed to detect Weakly Interacting Massive Particles (WIMPs) that scatter of xenon nuclei, the detector will also be sensitive to neutrinos coming from a supernova (SN) burst, within and beyond the Milky Way. These neutrinos interact through coherent elastic neutrino-nucleus scattering (CEvNS), a flavour-blind process that enhances the number of interacting neutrinos when compared with most neutrino detectors. Neutrinos from galactic SNe would also be observed in the ~700 t water-based muon and neutron vetoes of the experiment, increasing its sensitivity and discrimination potential.
With its tonne-scale target, low background rate, and ancillary water-based vetoes, XENONnT is capable of actively contributing to the SuperNova Early Warning System (SNEWS). In this poster we describe the sensitivity to galactic and extragalactic SNe of XENONnT and the framework developed to quickly and effectively communicate any potential SN burst to the SNEWS network in a matter of minutes.
The NOvA experiment uses the ~1 MW NuMI beam from Fermilab to study neutrino oscillations over a long distance. The experiment is focused on measuring electron neutrino appearance and muon neutrino disappearance at its Far detector situated in Ash River, Minnesota. NOvA was the first experiment in High Energy Physics to apply convolutional neural networks to the classification of neutrino interactions and the composite particles in a physics measurement. Currently, NOvA is crafting new deep-learning techniques to improve interpretability, robustness, and performance for future physics analyses. This poster will cover the advancements in deep-learning-based reconstruction methods being utilised in NOvA.
The ForwArd Search ExpeRiment (FASER) is located at the LHC at CERN, investigating long-lived, weakly interacting particles produced in the far-forward region of the ATLAS interaction point. The FASER$\nu$ detector is composed of alternating emulsion films and tungsten plates, with multiple yearly exposures, and focuses on high-energy collider neutrino interactions in the TeV regime, with the goal of extending current cross-section measurements in this new energy range. Both electron and muon neutrinos were detected by FASER$\nu$, and the first cross-section measurements in this energy range have been performed. To improve future results, the incident neutrino energy must be reconstructed using topological and kinematic variables of final state particles. For this purpose, we investigate the use of Neural Network techniques for the energy reconstruction. In this poster, recent FASER results and neutrino energy reconstruction methods developed are reported.
This poster presents the most recent T2K oscillation analysis results using 3.78×10^21
protons on target (POT) and highlights the expected sensitivity to the neutrino oscillation
parameters for the forthcoming next generation experiment in Japan - Hyper-Kamiokande
(Hyper-K).
By employing advanced methods for neutrino interaction modeling and neutrino flux
prediction, T2K data are analyzed to refine measurements of neutrino oscillation parameters
and explore CP violation in the lepton sector of the Standard Model. It is the first T2K
oscillation analysis including data after Gd loading in Super-K corresponding to 0.17x10^21
POT for neutrino mode. In addition, it includes an improved detector covariance matrix and a
new decay electron selection cut for both MC and data selection at Super-Kamiokande. A
90% confidence interval for the dCP parameter ranging from -3.04 to -0.34, and the p-value
for inverted ordering hypothesis of 0.0603 are some of the obtained results.
Looking forward to the Hyper-K era, comprehensive sensitivity studies were conducted
using inputs from previous T2K analyses and a new frequentist fitter. These studies
demonstrate Hyper-K's potential to further constrain oscillation parameters, offering valuable
insights for precise measurement and CP violation discovery. For instance, sensitivity studies
for dCP indicate that, with a true dCP of -π/2, CP violation can be determined with a 5-sigma
confidence level after 2 years of Hyper-K operation, achieving approximately 22% precision
for the dCP parameter.
Besides detecting ultra-high energy (UHE) cosmic rays, the Pierre Auger Observatory with its large Surface Detector array can also be used to search for neutrinos above $10^{17} \mathrm{eV}$. Using the data collected with the Observatory we have searched for both diffuse and point source fluxes of UHE neutrinos and to set some of the most stringent upper limits in the UHE range. Since its start it has also contributed to various multi-messenger follow-up searches of transient events. This contribution aims to present a summary of the various ongoing studies on the search for UHE neutrinos at the Pierre Auger Observatory. Updated upper limits to the diffuse flux of UHE neutrinos along with the latest results from UHE neutrino searches from binary black hole mergers will be presented. Additionally, potential improvements for the point source neutrino searches at the Pierre Auger Observatory with new techniques will also be discussed.
The Deep Underground Neutrino Experiment (DUNE), currently under construction, will use a high-intensity neutrino beam from Fermilab and observe the neutrinos in the near detector based at Fermilab and the far detector complex located at SURF. The DUNE near detector complex will host a suite of detectors that are currently in development. The experiment will make precision measurements of the neutrino oscillation parameters including the CP violation phase and the mass ordering. It is also sensitive to neutrinos from galactic supernovas.
One of the near detectors is The Muon Spectrometer (TMS) that will primarily detect and measure properties of the muons resulting from neutrino interactions exiting the preceding near detector. TMS will consist of alternating layers of plastic scintillators, in form of bars, and steel. The scintillator bars will be read out by WLS fibers and SiPMs and detect the scintillation light created by through-going charged particles.
The performance for different detector geometries was studied and will be presented in this poster.
Located underground, at the Gran Sasso National Laboratory, the Cryogenic Underground Observatory for Rare Events (CUORE) is a neutrinoless double beta ($0\nu\beta\beta$) decay experiment employing bolometric detectors. CUORE consists of an array of 988 TeO$_2$ crystals acting as both the source and the detector for the search of $0\nu\beta\beta$ decay in 206 kg of $^{130}$Te. Although the CUORE experiment is not optimized to be a particle tracker, the geometry and segmentation of CUORE allow the in-situ reconstruction of track-like events, such as cosmic-ray muons that do not get attenuated by the Gran Sasso mountains. The reconstruction of this kind of events in a 3D calorimeter lattice is a novel technique. In this poster, I present studies on the in-situ reconstruction of muon events and related induced backgrounds as well as the implications for CUPID, CUORE's successor.
The nuclear matrix element (NME) of neutrinoless double-β (0vββ) decay is an essential theoretical input for determining the neutrino effective mass, if the half-life of this decay is measured. The NME is also necessary for the detector design for the next generation of the 0vββ decay search. Reliable calculation of this NME has been a long-standing problem because of the diversity of the predicted values of the NME, which depends on the calculation method. A problem of the NME of the two-neutrino double-β (2vββ) decay of Xe-136 has been reported four years ago. The running sum for this NME of the shell model and the quasiparticle random-phase approximation (QRPA) were quite different. This means that the components of the NME are quite different depending on the calculations, and this problem affects the reliability of the predicted 0vββ NME.
In my poster presentation, first, I clarify that the cause of the problem is not the theoretical differences of the shell model and the QRPA; this is seen from available examples. Second, I clarify that the cause is in the interaction strengths; this is shown by my calculations and analytical discussion. In particular, it is seen that a decreasing behavior of the running sum at the energy of the Gamow-Teller giant resonance indicates a larger interaction strength than that of other calculations with less or no decreasing behavior. It is also shown that my interaction strength is appropriate by comparisons with experimental data related to the double-β decay.
The RES-NOVA project hunts neutrinos from the cosmos (e.g. Sun, Supernovae) via coherent elastic neutrino-nucleus scattering (CEνNS) using an array of archaeological lead (Pb) based cryogenic detectors. The high CEνNS cross-section on Pb and the ultra-high radiopurity of archaeological Pb enable the operation of a highly sensitive neutrino observatory, equally sensitive to all neutrino flavors, with dimensions at the cm-scale. The first phase of the RES-NOVA project is planning to operate a demonstrator detector with a total volume of about (30 cm)3. It will be sensitive to SN bursts from the entire Milky Way Galaxy with >3σ sensitivity while running PbWO4 detectors with a 1 keV energy threshold. The main SN parameters can potentially be constrained with high precision while looking at (anti-)νμ/τ. The innovative experimental approach allows for delivering important physics results also in other astroparticle physics sectors (e.g. Dark Matter) even when no SN is observed.
In this poster, the potential of this new experimental approach will be outlined, as well as complementary aspects with the currently used technologies. In addition, the experimental sensitivity and the performance of the first prototype detectors will be shown.
The Jinping Neutrino Experiment (JNE) is conducted at the China Jinping Underground Laboratory (CJPL), the deepest underground facility globally. JNE focuses on researching solar neutrinos, geo-neutrinos, supernova neutrinos, and neutrinoless double beta decay. The Jinping Neutrino one-ton prototype, located in CJPL-I, has completed measurements of cosmic rays and background. Currently, JNE is planning the construction of a low-background, multi-hundred-ton neutrino detector in CJPL-II by the end of 2026. Through simulations, the detector's geometry has been optimized, and structural design is finalized. The foundation pit excavation in D2 Hall of CJPL-II is complete. The upcoming detector will utilize novel 8-inch MCP-PMTs, currently undergoing testing. Our self-developed ADC have been tested on the one-ton prototype. Additionally, oil and water-based slow liquid scintillators (SLSs) have been developed. Reconstruction algorithms for SLSs have also been devised, enabling particle identification of electrons, gamma rays, and protons in the MeV-scale.
CUPID-Mo has served as a successful demonstrator experiment for CUPID (CUORE Upgrade with Particle ID), the planned next-generation upgrade of CUORE (Cryogenic Underground Observatory for Rare Events), a ton scale cryogenic calorimetric $0\nu\beta\beta$ decay experiment. CUPID-Mo operated at Laboratoire Souterrain de Modane (LSM) in France as an array of 20 enriched Li$_{2}$MoO$_{4}$ (LMO) cylindrical scintillating crystals (~200g ea.) each featuring a Ge light detector (LD) to collect scintillation light from the LMO. A dual mode of energy collection (heat from LMO and light from LDs) allows for event-by-event discrimination of $\alpha$ vs $\beta/\gamma$'s which reduces the background from degraded $\alpha$'s. CUPID-Mo has an energy resolution of ~7.4 keV (FWHM) at 3034 keV, complete $\alpha$ vs $\beta/\gamma$ discrimination and very low radioactive contamination.
Here we show the recent results of the analysis on the full CUPID-Mo exposure, showcasing improved analysis techniques with a focus on the development of the CUPID-Mo background model and latest results relating to the $2\nu\beta\beta$ decay half-life and spectrum. The background model was validated on a $^{56}$Co calibration dataset and is shown to describe the data quite well. We demonstrated the radiopurity of the LMO crystals meet CUPID goals and has an exceptionally low background index in the 3 MeV region of interest of ~2.7 x 10$^{-3}$ counts/keV/kg/yr. Owing to the relatively fast half-life and exceptionally well performing background model we also are able to show an updated result on the half-life of ~7.07 x 10$^{18}$ yr with a relative precision of 1.6% making it the most precise measurement to-date in $^{100}$Mo. Owing to the relatively fast half-life we are able to comment on the $2\nu\beta\beta$ decay spectral shape, constraining higher order corrections. CUPID-Mo also performed a novel measurement of the shape factor, and extracted a value for the axial vector coupling constant.
NOvA and T2K represent the two current-generation long-baseline neutrino oscillation experiments. Their complementarity in terms of detector design, analysis strategy, baseline, and neutrino beam energy has the potential to provide further insight into the observed degeneracies in the oscillation parameter space. The first joint NOvA-T2K analysis incorporates datasets from each experiment into a unified framework using the detailed likelihoods and consistent statistical treatment across the full dimensionality. This poster outlines the methods and results from the joint analysis, which demonstrates the simultaneous compatibility of both datasets and provides a strong constraint on $|\Delta m^2_{32}|$.
The MINOS(+) experiment has pioneered the two-detector method used for neutrino oscillation physics widely used today. It collected data from 2005 to 2016 using two tracking iron scintillator calorimeters, a Near detector close to the NuMI neutrino beam source at Fermilab, and a Far detector 735km away, deep underground in the Soudan Mine in Minnesota. An improved analysis of the full beam data set will be presented, looking at how different phenomena such as meson-exchange-currents may affect the MINOS results, and also how the results are affected by applying external data constraints.
The search for gamma ray counterparts of IceCube neutrino events is of paramount important for understanding the role of blazars as candidate sources of cosmic high energy neutrinos. We have searched in the AGILE gamma-ray satellite public archive the counterparts of a sample of IceCube neutrinos events detected between September 2018 and March 2020. We present the candidate sources in the error box centered on the detected neutrinos and their multi-frequency light curves and Spectral Energy Distributions, providing estimates of the gamma ray flux above 100 MeV for the AGILE detections. The possible associations with blazars and the role of blazar type are discussed.
The strength of multi-messenger astronomy allows to deeply investigate the Universe by combining observations with diverse messengers, such as photons, gravitational waves, high-energy charged particles and neutrinos. The chance of detecting new astrophysical sources is increased by a coincident detection, which motivates several observatories to send external alerts and perform follow-ups.
The deep-sea KM3NeT Cherenkov telescope is currently being constructed in the Mediterranean sea with ORCA off-shore Toulon (France), and ARCA off-shore Capo Passero in Sicily (Italy). Being sensitive to an extended neutrino energy range (from MeV to PeV energies), KM3NeT is playing an active role in the context of multimessenger astronomy.
This contribution presents the latest results of the real-time search (follow-up) for neutrinos in coincidence with astrophysical sources performed with the real-time multi-messenger analysis framework.
The separate observation of Cherenkov and scintillation light in liquid scintillation media and thus the extraction of a directional signal and excellent energy and vertex resolution holds great potential in current R&D projects for large scale neutrino detectors like JUNO or Theia. This method offers promising prospects in background suppression methodologies. In particular, the ability to identify and thereby reduce the unshieldable background of solar neutrino events provides a decisive improvement of liquid scintillation detectors searching for the neutrinoless double beta decay. This potential arises from the combination of newly developed slow liquid scintillators doped with potential double beta decay candidates tellurium or xenon and state-of-the-art photon sensors. To study the fundamental properties of these novel detection media, including slow liquid scintillators, a new setup exploiting the principle of time-correlated single photon counting with cutting-edge photomultiplier tubes is under commissioning at the Technical University of Munich (TUM). The experiment enables detailed studies of the probability density function of the photon emission from the scintillation medium including both Cherenkov and scintillation light. A separation can be achieved either by direct timing, geometry with respect to the Cherenkov light direction or chromatic sorting via optical bandpass filters. On the poster the design of this novel table-top experiment is presented as well as first measurement results with several organic liquid scintillator cocktails. This work has been supported by the Cluster of Excellence PRISMA+, the Cluster of Excellence ORIGINS as well as the Collaborative Research Center Neutrinos and Dark Matter in Astroparticle Physics (SFB1258) and the DFG Research Units 2319 and 5519.
We searched for 10-1,000 GeV neutrinos from 2,268 gamma-ray bursts of IceCube-DeepCore data collected between April 2012, and May 2020. We have also conducted the same search for the "brightest of all time" (BOAT) GRB 221009A. We find no evidence of neutrino emission from these GRBs. We present model-independent limits on neutrino emission from these GRBs for various time scales that overlap with prompt, precursor and early afterglow phases. If the fireball is baryon loaded, this leads to subphotospheric neutron-proton collisions. We find that GRB 221009A provides the most constraining limit on the baryon loading. Assuming a jet Lorentz factor of 300 (800), the baryon loading on GRB 221009A is lower than 3.85 (2.13) at a 90% confidence level. The canonical value of baryon loading in models is 5.
The ANTARES neutrino telescope took data from 2007 to 2022, collecting a high-purity sample of high-energy neutrinos. This sample can be used to search for a diffuse flux of cosmic neutrinos, emerging at the highest energies above the atmospheric backgrounds. A mild excess of cosmic neutrinos has been observed in the ANTARES dataset covering the first 11 years of data taking. In this contribution, the final update to such search will be presented, including all-flavour neutrino interactions collected over the 15-year lifespan of ANTARES, with an improved energy reconstruction and reduced systematic uncertainties.
IceCube has made significant progress in identifying astrophysical sources of high-energy neutrinos. However, the majority of the majority of the astrophysical flux remains unexplained, prompting further investigation. To improve our understanding of this flux and its sources, it is important to investigate the presence of a component at lower neutrino energies. To this end, we propose a study that searches for GeV neutrinos associated with neutrino events above 60 TeV of reconstructed energy. Since the specialized event selection sensitive in this range is dominated by atmospheric backgrounds, we focus on a hypothesis of short transient neutrino sources, which would then produce both high-energy and GeV neutrino in time correlation. The classes of astrophysical transients already proposed as GeV neutrino sources such as collapsars serve to motivate the assumed emission time scale. In this poster, we show the statistical method and sensitivity of this search as well as the data quality checks to be performed.
The KM3NeT experiment is a next-generation neutrino telescope, consisting of the ORCA and ARCA detectors, organised as 3D arrays of light sensors, and immersed in the depths of the Mediterranean Sea. Identical in their design but differing by scale, ORCA aims at detecting neutrinos in the GeV-TeV range, while ARCA will focus on higher energies in the TeV-PeV range. Both detectors can contribute to the study of multi-messenger phenomena, that is observing different types of astrophysical messengers from the same source to infer the multiple aspects of the emitting source. Typically, these messengers are neutrinos, cosmic rays, gravitational waves and electromagnetic radiations.
Among the latter, Fast Radio Bursts (FRB) are good candidates for multi-messenger emissions due to the huge energy involved in their bursts. However, neutrino emissions from FRB sources are poorly constrained by models, which motivates a search across both detector energy ranges and does not exclude temporal coincidences. In this contribution, I will present the method and criteria of a multi-messenger analysis intended to search for spatial and temporal coincidences of astrophysical neutrino signals from the ARCA and ORCA detectors with a FRB catalogue on which a selection has been applied, taking into account the date and location of the observed bursts.
The measurement of the unexpectedly high value of the third neutrino mixing angle, $\theta_{13}$, opened the possibility of measuring the Dirac leptonic CP violating angle, $\delta_{CP}$ , using intense neutrino beams. The European Spallation Source neutrino Super Beam (ESS$\nu$SB) is a long-baseline neutrino project that aims in measuring CPV in the leptonic sector at the second of the $\nu_{\mu}$ to $\nu_{e}$ oscillation maximum, where the sensitivity is ∼ 3 times higher than that at the first maxima. The use of the 5 MW proton beam of the ESS linac combined to a ∼ cubic-km Water Cherenkov detector located at the second oscillation maximum paves the way to a precise measurement of $\delta_{CP}$. The ESS$\nu$SB CDR showed that after 10 years of data taking, more than 70% of the $\delta_{CP}$ range will be covered with 5$\sigma$ C.L. to reject the no-CP-violation hypothesis. The expected value of $\delta_{CP}$ precision is smaller than 8$^\circ$ for all $\delta_{CP}$ values.
The next phase of the project, the ESS$\nu$SB+, which started in 2023, aims in using the intense muon flux produced together with neutrinos to measure the neutrino-nucleus cross-section (the dominant term of the systematic uncertainty) in the energy range of 0.2 to 0.6 GeV, using a LEnuSTORM and a LEMNB facilities.
In this poster, an overview of the concluded phase and an update on the first-year design-study of the current phase of the project will be presented.
The high-energy neutrino telescope ANTARES was a $0.01 $~km$^3$ volume detector located in the Mediterranean Sea. It operated from 2007 until the beginning of 2022, accumulating more than 15 years of data. The ANTARES neutrino telescope main goal was to identify neutrinos from astrophysical sources particularly those of Galactic origin, using its sensitivity to neutrino coming from the Southern Sky with energies below 100 TeV, and its excellent angular resolution.
The ANTARES Collaboration has been consistently updating the results of these studies, incorporating all the data available at the time. With ANTARES decommissioned, the final update to this analysis using the complete dataset is presented and discussed in this contribution. The result includes a study of Galactic and extragalactic candidate sources for neutrino emission, both point-like or extended. Furthermore, it includes a search for neutrino clustering across the entire sky visible for the ANTARES telescope, along with a dedicated survey of the Galactic Plane.
The NEXT experiment aims at the sensitive search of the neutrinoless double beta decay ($\beta\beta0\nu$) in $^{136}$Xe, using high-pressure gas electroluminescent time projection chambers. After the successful operation of the NEXT-White detector, which performed the first searches of the double beta decay with the novel NEXT technology using a limited amount of Xe ($\sim$5 kg), the collaboration has started the operation of the NEXT-100 detector. This detector, holding up to 80 kg of Xe at 15 bar, was installed during 2023 in the Laboratorio Subterr\'aneo de Canfranc (LSC), and it is currently undergoing a commissioning and calibration stage. NEXT-100 is equipped with 60 PMTs for the detection of the primary scintillation light and the energy measurement, as well as with 3584 SiPMs meant to provide the topological signature of the events. According to an extensive radiopurity screening campaign, and the energy resolution ($<1$% FWHM) and topology-based background rejection factors measured in NEXT-White, the expected background index in NEXT-100 is below 10$^{-3}$ counts/keV/kg/year. This corresponds to a sensitivity to the half-life of the $\beta\beta0\nu$ decay of 6$\times$10$^{25}$ yr (90% C.L.), after 3 years of data taking. This detector will also set the grounds for the construction of a ton-scale detector, NEXT-HD, boosting the sensitivity above 10$^{27}$ yr. Thus, after the first years of operation, NEXT-100 will be upgraded to demonstrate the advanced readout solutions to be implemented in NEXT-HD.
Multiple experiments are utilizing the polar icecaps to detect ultra-high energy neutrinos via radio emission. They employ antennas embedded to depths of up to 200 metres. This places them within the firn layer, where the density and hence refractive index increase with depth. Glaciological models demonstrate that the firn density varies with time over a seasonal timescale. The resulting variable refractive index will transform the properties of in-ice radio signals, resulting in a systematic uncertainty in the reconstruction of the neutrino energy and arrival direction. An effort to quantify these uncertainties is underway by simulating radio propagation for a range of source and receiver positions at Summit station, Greenland, with the refractive index based on ice core measurements and glaciological modeling. Our first observation is that the amplitude and arrival time of the secondary or ‘refracted’ signal is generally variable, including for deep neutrino interaction depths on the order of the radio attenuation length.
The Pacific-Ocean Neutrino Experiment (P-ONE) is a high energy neutrino telescope under development off the coast of Vancouver Island, Canada. A construction site has been chosen in the Cascadia Basin, a large flat seabed on the Juan de Fuca plate. The P-ONE collaboration previously operated the STRings for Absorption length in Water (STRAW) and STRAW-b pathfinder missions. These instruments measured the water attenuation length and background light spectrum and were deployed to the Cascadia Basin site in 2018 and 2020 respectively. Both moorings were retrieved in July 2023. Measurements were made of the evolution of the optical surfaces on STRAW, showing a fouling effect on upwards facing modules near the seafloor. A pre-recovery survey and the retrieval showed both a buildup of sediment as well as colonization by marine organisms, and samples were taken for identification. The change in transmission efficiency has been measured across the five year lifespan of the original STRAW detector. Biologically inspired models have been used to model and help understand the time dependence of fouling on the glass housing. This contribution covers the measurements, modelling and identification of sedimentation and biological fouling in the P-ONE pathfinders as well as the ongoing development of mitigation strategies.
Neutrino physics has entered into the precision era. The unprecedented accuracy in the experimental measurement necessitates reliable theoretical predictions at the loop level. In order to confront neutrino mass models at high-energy scales with low-energy precision data, we accomplish a complete one-loop matching of canonical seesaw models onto the Standard Model Effective Field Theories and derive the Wilson coefficients of all dimension-six operators. Together with the relevant renormalization-group equations, this provides a self-consistent theoretical framework to carry out one-loop calculations of low-energy observables and test neutrino mass models.
Gamma-ray observations of astrophysical neutrino sources are fundamentally important for understanding the underlying neutrino production mechanisms. We investigate the Cherenkov Telescope Array Observatory (CTAO) prospects for detecting the very-high-energy (VHE) gamma-ray counterparts to neutrino-emitting extragalactic sources. The performance of CTAO under different configurations (including the so-called "Alpha" and "Omega" configurations) is computed based on neutrino and gamma-ray simulations of steady sources and of flaring blazars, assuming that the neutrino events are detected with the IceCube neutrino telescope. The detection probability for CTAO is calculated for both sites of the Observatory, taking into account visibility constraints. We find that, under optimal observing conditions, within 30 minutes of observation, CTAO could detect the VHE gamma-ray emission associated with at least 3 neutrino events per year. We investigate the detectability of the blazars given either 1 or 5 h observation windows.
IceCube DeepCore, the existing low-energy extension of the IceCube Neutrino Observatory, was designed to lower the neutrino detection energy threshold to the GeV range. A new extension, called the IceCube Upgrade, will consist of seven additional strings installed within the DeepCore fiducial volume. These new strings will host modules with spacings of about 20 m horizontally and 3 m vertically, compared to about 40-70 m horizontally and 7 m vertically in DeepCore. It will be deployed in the polar season of 2025/26. This additional hardware features new types of optical modules with multi-PMT configurations, as well as calibration devices. This upgrade will more than triple the number of PMT channels with respect to current IceCube, and will significantly enhance its capabilities in the GeV energy range. However, the increased channel count also poses new computational challenges for the event simulation, selection, and reconstruction. In this contribution we present updated oscillation sensitivities based on the latest advancements in simulation, event selection, and reconstruction techniques.
The nEXO experiment aims to study neutrinoless double-beta decay, requiring stringent control of radioactive backgrounds. Traditional printed circuit boards (PCBs) used for mounting Silicon Photomultipliers (SiPMs) can introduce unacceptable levels of radioactivity. To overcome this challenge, we have developed a novel Silicon Interposer technology utilizing cutting-edge Through-Silicon Via (TSV) fabrication.
Manufactured from high-purity silicon wafers, the Silicon Interposer provides a low-radioactivity platform for mounting SiPMs while enabling high-density interconnections. We have produced three generations of prototypes, iteratively refining the design and manufacturing process.
The silicon interposers have undergone rigorous testing, including electrical characterization, mechanical assessments, temperature cycling, and signal integrity evaluation with mounted SiPMs. The results demonstrate successful integration, meeting the stringent radioactivity and performance requirements for the nEXO experiment.
This poster presents the innovative Silicon Interposer technology, detailing the design, fabrication process, and comprehensive test results. The Silicon Interposer offers a compelling low-radioactivity solution for SiPM mounting, enabling enhanced sensitivity in rare-event search experiments like nEXO.
The LEGEND-200 experiment, currently running at LNGS, seeks to measure neutrinoless double beta decay in Ge-76 using a source=detector experimental setup with a discovery potential up over $10^{28}$ years and covering the inverted hierarchy. The sensitivity reach of this experiment is based on an accurate understanding of the expected backgrounds and the expected detector response to a wide variety of event topologies, in particular alpha and beta events impacting the corresponding passivated/n+ sensitive surfaces of the various LEGEND-200 detectors. To this end, we have developed a combined electromagnetic and Geant4 simulation framework which can model the full detector response based on known detector efforts such as surface charge. In this poster we will present the setup of these simulations and their results as well as an estimate for the potential effect of the detector response to the overall LEGEND-200 background budget.
Acknowledgements:
This work is supported by the U.S. DOE and the NSF, the LANL, ORNL and LBNL LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Russian RFBR; the Canadian NSERC and CFI; the LNGS, SNOLAB, and SURF facilities.
While IceCube's detection astrophysical neutrinos at energies up to a few PeV has opened a new window to our Universe, much remains to be discovered regarding these neutrinos' origin and nature. In particular, the difficulty differentiating $\nu_{e}$ and $\nu_{𝜏}$ charged-current (CC) events in the energy limits our ability to measure precisely the flavor ratio of this flux. The Tau Air-Shower Mountain-Based Observatory (TAMBO) is a next-generation neutrino observatory capable of producing a high-purity sample of $\nu_{𝜏}$ CC events in the energy range from 1-100 PeV, i.e. just above the IceCube measurements. An array of water Cherenkov tanks and plastic scintillators deployed on one face of the Colca Canyon will observe the air-shower produced when a 𝜏 lepton, produced in a $\nu_{𝜏}$ CC interaction, emerges from the opposite face and decays in the air. In this contribution, I will present the current status of the TAMBO simulation, including preliminary sensitivities to various flux models and potential for point source searches.
LiquidO is an innovative technology that uses opaque liquid scintillators for particle detection. A LiquidO scintillator combines a short scattering length and a long absorption length to confine optical photons close to their creation point. A fine array of wavelength-shifting fibres is used to collect and transport the scintillation light to readout SiPMs. A LiquidO detector will have unprecedented position resolution compared to current transparent scintillators and be capable of particle identification via event topology. Proof of principle has been demonstrated by two prototypes with a third currently under construction.
The CLOUD collaboration is designing a 5-10 ton LiquidO neutrino detector. This will be an above-ground ultra-near reactor neutrino detector located in the Chooz nuclear power plant in France. This detector is the byproduct of the AntiMatter-OTech EIC/UKRI-funded project, and has both research and industry capabilities such as measuring the absolute reactor anti-neutrino flux and reactor monitoring.
This poster will discuss simulations of the CLOUD inner detector including particle identification via event topology and fibre array design. In designing the fibre array we aim to optimise reconstruction along the fibres (z-direction) without compromising the reconstruction of energy or position perpendicular to the fibres (x and y). Two broad fibre array designs are considered: z-parallel and stereo shells. A z-parallel array could achieve mm resolution in x and y, with z-position obtained at lower resolution from signal timing and intensity differences. A stereo shell array would improve the resolution in z but presents challenges for the triggering and reconstruction of events as well as the construction of the detector.
In our model, all the CKM mixing of the quarks and MNS mixing of the leptons has one source, namely a mixing of the fermions of the Standard Model with a set of vector-like fermions in the context of SU(5) grand unification. Because the mixing of the 5 bar multiplets can be described by a single 3x3 matrix, a highly predictive model result. We showed that the 9 mass and mixing parameters of the neutrinos can be determined in terms of just 5 free parameters of the model. This leads to predictions of the Dirac CP phase of the neutrinos, the mass of the lightest neutrino and the two Majorana neutrino phases.
In this work, simple approximate analytical formulas for the predictions of the model are derived. So that as new measurements are made, revised predictions can easily be extracted. This would allow one to determine which measurements would best test the model without doing the entire global numerical fit over again. About the phenomenology of vector-like fermions, for the models involve the existence of new vector-like fermion multiplets, if these have masses near the weak scale, their phenomenology is worth investigating.
On behalf of the KM3NeT Collaboration
KM3NeT/ARCA is a Cherenkov neutrino telescope currently under construction in the Mediterranean Sea, at 100 km off the Sicilian coast, near Capo Passero, and at about 3500 m depth. On its final configuration, the detector will instrument a cubic kilometer
volume of seawater. At the present moment, 28 detector units have been already deployed. In this contribution, we analyze a catalogue of 75 Ultra-Luminous Infrared Galaxies (ULIRGs) as potential neutrino emitters, in light of the latest experiment data. In particular, we not only perform a single source search along the catalogue but also
conduct a binned likelihood stacking search. We present the 90% sensitivity on their emissions, also extrapolating these limits to the entire source population.
The Beryllium Electron capture in Superconducting Tunnel junctions (BeEST) experiment searches for the signatures of heavy neutrino mass eigenstates by measuring the recoil energy of the Li-7 daughter nucleus from Be-7 electron capture decay. In Phase-II, BeEST has set leading limits on neutrino mixing to a heavy eigenstate in the 100-850 keV mass range using a single superconducting tunnel junction detector. The current Phase-III has expanded the BeEST experiment to a 32-pixel STJ array detector and increased the dose of implanted Be-7. In this poster, we present the status of the BeEST Phase-III and highlight the refined experimental and analytical techniques in Phase-III. We also discuss an improved analysis scheme using pulse shape discrimination enabled by a new continuous data acquisition system.
The Short Baseline Neutrino (SBN) programme has an extensive physics program where one of the key aims is to investigate the existence of light sterile neutrinos. It comprises three LArTPC detectors along the Booster Neutrino Beam (BNB); a primarily-muon-neutrino beam. The near detector of the programme (SBND) will carry the main burden of reducing systematic error for the programme due to its proximity to the target. With unprecedentedly high statistics and excellent imaging capabilities, the detector will fully characterise the neutrino flux and neutrino-Argon cross-section and enable sensitive light sterile neutrino oscillation searches. Critically, due to its short baseline, SBND is sensitive to very fast oscillations, indicated by large squared mass splittings and hinted to by previous experiments as the region of phase space relevant for light sterile neutrino searches.
The PRISM concept exploits the relation between the off-axis angle of the beam and the flux energy spectrum; moving off-axis from the beam centre results in the spectrum of neutrino energies peaking at lower values. Therefore, by combining measurements at different beam off-axis angles it is possible to reduce the corresponding systematic uncertainties. Due to its proximity to the beam and slightly asymmetrical placement with respect to the beamline, SBND sees up to 1.6 degrees off-axis, making it ideal to exploit this technique. The work presented here will cover preliminary SBND sensitivity results and discuss the effects of using PRISM. This work used the VALOR Neutrino Fitting Framework. It will support a standalone analysis of each oscillation channel and joint multi-channel analyses to provide robust systematic constraints and definitive tests of the light sterile neutrino hypothesis.
The Deep Underground Neutrino Experiment (DUNE) is a next generation neutrino oscillation experiment that aims to provide insight towards the main outstanding questions in neutrino physics like mass hierarchy and investigating the potential existence of CP violation. It will make use of a suite of large liquid argon (LAr) time projection chambers, 1.5 km deep underground and located 1300 kilometers from the Fermilab LBNF beamline in the US.
Neutrinos are one of the best probes towards physics beyond the Standard Model. A highly sought-after hypothesis is the existence of one or more "sterile" neutrinos, which could be possible candidates for dark matter. The DUNE experiment will present a good opportunity to further expand this search, thanks to its expected excellent event reconstruction capabilities.
This initial study provides a largely phenomenological but realistic estimation of the DUNE Far Detector's sensitivity to detect sterile neutrinos using data from atmospheric events. A detailed exploration of the dependance on detector and analysis parameters, such as reconstruction efficiencies, has been performed. Upgoing atmospheric neutrino events will provide sufficient statistics and allow exploration of a wider range of L/E than beam data assuming an exposure of 10 kt/year. Results are presented from an Asimov data minimum log-likelihood fit considering a "3+1" model and including a realistic parameterization of detector reconstruction uncertainties.
Work is on-going towards a full simulation study within the framework allowing joint fits with other oscillation analyses.
The goal of the SuperNEMO experiment is the search for neutrinoless double-beta decay (0𝜈𝛽𝛽), the observation of which would prove that the neutrino is a Majorana particle. As 0𝜈𝛽𝛽 is a hypothetical and extremely rare process, it is essential to have the lowest level of background possible. 222Rn is a gaseous isotope which could emanate from the detector materials or diffuse from the air of the laboratory into the detector, and its daughter isotope 214Bi with Qb=3.27 MeV can contribute to the double-beta background. The 222Rn activity inside the SuperNEMO tracker demonstrator module must be significantly reduced down to 0.15 mBq/m3. This poster will detail anti-radon strategies used in SuperNEMO and present the status of the 222Rn analysis based on first data compared to simulation using the topology of the 214Bi-214Po decay event, i.e. one electron followed by a delayed alpha.
Study of the cosmogenic background in Te-LS [subgroup study]
Hechong Han
The Jiangmen Underground Neutrino Observatory (JUNO) is a world-leading neutrino project, aiming at determining the mass ordering of neutrinos through precise measurements of neutrino oscillations. After the determination of neutrino mass ordering, JUNO Phase II will be used to explore neutrinoless double beta decay beyond the standard model. If a group of nuclides capable of undergoing this decay is universally found in experiments, it would prove that neutrinos are Majorana particles, making neutrinos the first known Majorana fermions. The challenge in detecting neutrinoless double beta decay lies in the extremely low number of rare decay events. Even with a 20-kiloton liquid scintillator in JUNO, the expected number of events observed in a year, with an anticipated 3% mass fraction of Te (natural abundance), would only be of the order of tens at an assumed halflife of 1e28 yr. Therefore, discriminating and reducing background are crucial. This poster will focus on the impact and exclusion strategies of long-lived isotope backgrounds induced by high-energy muons on Te nuclei. The long-lived isotopes yields are calculated using simplified geometries in G4 and fluka. Differences introduced between different hadronic models between G4 and fluka are also compared. Graph neural networks(GNN) are used for background rejection
The presence of a super-light sterile neutrino can lead to a dip in the survival probability of solar neutrinos, and explain the suppression of the upturn in the low energy solar neutrino data. In this work, we systematically study the survival probabilities in the 3+1 framework by taking into account of the non-adiabatic transitions and the coherence effect. We obtain an analytic equation that can predict the position of the dip. We also place constraints on the parameter space of sterile neutrinos by using the latest Borexino and KamLAND data. We find that the low and high energy neutrino data at Borexino are sensitive to different regions in the sterile neutrino parameter space. In the case with only $\theta_{01}$ being nonzero, the $\rm{{}^{8}B}$ data sets the strongest bounds at $\Delta m_{01}^{2} \approx (1.1\sim2.2)\Delta m_{21}^{2}$, while the low energy neutrino data is more sensitive to other mass-squared regions. The lowest bounds on $\Delta m_{01}^{2}$ from the $\rm{pp}$ data can reach $10^{-12} \ \rm{eV^{2}}$ because of the coherence effect. Also, due to the presence of non-adiabatic transitions, the bounds in the range of $10^{-9} \ \textrm{eV}^{2} \lesssim \Delta m_{01}^{2} \lesssim 10^{-5} \ \textrm{eV}^{2}$ become weaker as $\Delta m_{01}^{2}$ or $\sin^{2}2\theta_{01}$ decreases. We also find that in the case with only $\theta_{02}$ or $\theta_{03}$ being nonzero, the low energy solar neutrino data set similar but weaker bounds as compared to the case with only $\theta_{01}$ being nonzero. However, the bounds from the high energy solar data and the KamLAND data are largely affected by the sterile mixing angles.
This contribution focuses on a small-scale liquid scintillator detector, serving as a test setup for the Jiangmen Underground Neutrino Observatory (JUNO) experiment. JUNO is a next-generation medium baseline neutrino experiment located in China. The experiment has a broad physics program and the main goals are to determine the neutrino mass ordering and measure three oscillation parameters with sub-percent precision. JUNO's central detector is an acrylic sphere $\sim$35.4 meters in diameter filled with 20 kt of liquid scintillator. It is equipped with 43212 photomultiplier tubes (PMTs) providing $\sim$75% of photo-coverage. As the detector approaches its final commissioning phase, comprehensive testing of various components of the experiment is crucial.
The presented test setup, located at Legnaro National Laboratory in Italy, consists of $\sim$20 kg of JUNO liquid scintillator watched by 48 2-inch PMTs. This setup is equipped with JUNO's readout electronics and data acquisition (DAQ) and it was mainly designed as a test-bench for the full processing chain.
In this contribution, we present preliminary results on the feasibility of tagging time-correlated events, exploiting the $^{214}$Bi-$^{214}$Po $\beta$-$\alpha$ coincidence.
To ensure accurate energy measurements, we performed an energy calibration using several radioactive sources. The calibration procedure establishes a precise energy scale, essential for subsequent analyses.
$^{214}$Bi-$^{214}$Po coincidences, characterized by a time difference of approximately 230 $\mu$s, close to the timing of JUNO's main signal, inverse beta decay events, provide an opportunity to test part of the selection strategy. The results show approximately 10 thousand $^{214}$Bi-$^{214}$Po candidates acquired after $\sim$15 hours of data acquisition.
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino oscillation experiment with a broad physics program centered on the study of neutrinos. While prototypes of various component detectors have already collected data, the 2x2 Demonstrator, a prototype for DUNE’s liquid argon near detector (ND-LAr), will be the first DUNE detector to collect neutrino beam data and support neutrino physics analyses. Installed in the Neutrinos at the Main Injector (NuMI) neutrino beamline at Fermilab and scheduled to begin data taking in spring 2024, the 2x2 Demonstrator boasts key DUNE ND-LAr design components including Liquid Argon Time Projection Chamber (LArTPC) technology, a modular structure, and pixel-based charge readout. Neutrino beam data collected with the 2x2 Demonstrator will be essential in validating DUNE ND-LAr design capabilities and will form the basis of DUNE’s first neutrino physics measurements. This poster gives an overview of the 2x2 Demonstrator and some of its initial neutrino physics analysis targets.
Cryogenic particle detectors represent a promising avenue for conducting experiments on neutrinoless double beta decay, as demonstrated by the successful operation and sensitivity of current and previous experiments such as CUORE, CUPID-0 and CUPID-Mo. However, the development of new bolometric technologies for effective background rejection is needed to get a higher sensitivity to the 0𝜈𝛽𝛽 decay in future experiments.
CROSS (Cryogenic Rare-event Observatory with Surface Sensitivity) aims at studying and optimizing bolometric techniques for next-generation neutrinoless double beta decay experiments of $^{100}Mo$ and $^{130}Te$. Situated at the Laboratorio Subterráneo de Canfranc (LSC) in Spain, the final CROSS demonstrator will include 36 $Li_2MoO_4$ crystals and 6 $TeO_2$ crystals of size $4.5⨯4.5⨯4.5\;cm^3$ facing 42 Neganov-Trofimov-Luke (NTL) Germanium light detectors divided into 3 towers. The commencement of operation of the final experiment is scheduled for the end of 2024. Currently, one tower containing one-third of the final demonstrator's configuration is undergoing testing at LSC.
One of the objectives of our tests is the evaluation of the performance of the NTL light detectors, crucial for the rejection of alpha particles and random coincidences of ordinary 2𝜈𝛽𝛽 decay of $^{100}Mo$. Simultaneously, efforts are underway to develop and test thin-film crystal coating techniques aimed at surface events discrimination. In this poster, we will provide an overview of the current status of the CROSS experiment, discussing the achieved detector performance - energy resolution, $\alpha/\beta$ discrimination power, pile-up rejection capability - along with the physics reach of the CROSS demonstrator.
Neutrinoless double-beta decay (0νββ) plays a crucial role in addressing some of the major outstanding issues in particle physics, including lepton number conservation and the Majorana nature of neutrinos. Over the past few decades, several efforts have sought to increase the sensitivity on the 0νββ process to target the Inverted-Ordering region of the neutrino mass spectrum. Forthcoming-generation experiments plan to fulfil this promise aiming at sensitivities beyond 1E27 years on the 0νββ half-life.
Among the employed techniques, low-temperature calorimetry has proven to be highly promising and is poised to maintain this role in the near future through the CUPID experiment. CUPID, the CUORE Upgrade with Particle IDentification, is a next-generation experiment that will search for 0νββ of 100-Mo and other rare events using Li2MoO4 scintillating bolometers. CUPID will take advantage of the experience acquired by running CUORE (Cryogenic Underground Observatory for Rare Events), the first tonne-scale bolometric array, currently operating at Laboratori Nazionali del Gran Sasso in Italy. CUPID will be hosted in the existing CUORE cryogenic infrastructure deploying 1596 scintillating Li2MoO4 crystals enriched in 100-Mo, coupled to 1710 light detectors. The simultaneous readout of heat and light, allows for particle identification and a robust rejection of the previously leading background from alpha particles.
Today, coordinated efforts have validated the main science drivers and put in place a viable procurement chain. Ongoing activities are focused on finalizing the CUPID detector design and refine its performance and physics capabilities. In the poster, we will provide an overview of the current status of CUPID and highlight the upcoming milestones in the construction of the experiment.
The DUNE (Deep Underground Neutrino Experiment) project is a future long-baseline neutrino oscillation experiment. The primary objectives of DUNE include measuring the neutrino CP-violating phase, establishing the neutrino mass hierarchy, and conducting a broad physics program that encompasses studies of supernovae, low-energy physics, and searches for physics beyond the Standard Model. Central to achieving these objectives, DUNE will deploy two far detectors, each leveraging distinct technological innovations to capture and analyze neutrino interactions. The first detector will employ a well-established single-phase horizontal-drift liquid-Argon Time Projection Chamber (TPC) that utilizes conventional wire-chamber technology. In contrast, the second detector is set to pioneer a groundbreaking "vertical drift" TPC, replacing wires with charge readout planes (CRPs) accommodating strips on perforated PCB anodes for the charge readout. Following the success of small-scale prototypes, full-scale CRP demonstrators have been built and tested extensively at the CERN neutrino platform.
This poster will present the design nuances of the "vertical drift" CRPs, highlight critical insights for CRP assembly, and will present preliminary results from the demonstration phase.
The next generation of neutrino experiments promises significant progresses in physics beyond Standard Model with a high discovery potential regarding in particular the matter/antimatter asymmetry and the mass hierarchy. One of the key points will be to use high intensity neutrino superbeam in combination with megaton scale detectors.
In Europe, the ESSnuSB project realized a conceptual design study of a new superbeam facility based on the 5 MW proton linac of the European Spallation Source. This facility will offer the possibility measure the $\delta_{CP}$ phase at 8° precision level.
The new phase of the project, called ESSnuSB+, will investigate the possibility to add complementary facilities like a Low Energy nuSTORM ring and a Low Energy Monitored beam to study complementary physics such the cross-section measurement and the sterile neutrino hypothesis.
This new project will adapt the concept of a the ESSnuSB target station to the requirements of the complementary facilities. In this poster, the progress of the ESSnuSB+ Target Station study will be presented.
The ESSnuSB (European Spallation Source neutrino Super Beam) project is a design study for an experiment to measure the CP violation in the leptonic sector by observing neutrino oscillations in the second oscillation maximum. The high intensity neutrino beam will be produced using the ESS (European Spallation Source) proton linear accelerator, which will be the most powerful proton driver in the world at the 5 MW average beam power. The ESSnuSB experiment is foreseen to be implemented in a staged approach. In the first phase of the project there will be a comprehensive campaign to measure neutrino-water interaction cross sections using the monitored neutrino beam similar to ENUBET project and the neutrino beam from the low-energy nuSTORM ring. The construction of the large 540 kt fiducial mass water-Cherenkov far detectors is expected to proceed in parallel with the cross-section measurement campaign; once they are completed, the second phase of the experiment will start in which the actual CP violation measurement will be performed. This poster will give an overview of the current design of the ESSnuSB detectors, both at the near and the far detector sites.
In the budding field of multi-messenger astrophysics, neutrino observatories such as IceCube play a crucial role in identifying targets of opportunity with their near 100% up-time and view of the whole sky. IceCube aims to identify sources of astrophysical neutrinos using a cubic kilometer of instrumented ice located at the South Pole. Many candidate neutrino sources, such as blazars, have time-variable emission observed in various wavelengths of light. Therefore, flares in photons that coincide in direction and time with neutrino signatures help to distinguish true neutrino flares from background fluctuations. Such a source was identified when IceCube reported a high-energy neutrino from the direction of TXS 0506+056 and the resulting follow-up found the blazar to be in a flaring state across the electromagnetic spectrum including very-high-energy gamma rays (E > 100 GeV). Here we discuss a specific channel of IceCube alerts known as the gamma-ray follow-up (GFU) alerts which seeks to identify significant clusters of neutrinos in time and space, such as that found from TXS 0506+056, with low latency to trigger follow-up by telescopes. The stream has been operating in its current configuration since 2019 and has been sending alerts to partner imaging air Cherenkov telescopes. We will present results from an offline analysis of IceCube’s archival GFU data from May 2011 to October 2022 in which we identified the most significant flares. We also present concepts for future updates to the GFU stream to improve its performance using updated event reconstruction techniques, new source lists employing updated gamma-ray data and models of neutrino emission, and collaborations with other telescope partners including other neutrino telescopes.
In order to be ready for the era where statistical uncertainty will not be dominant anymore, the T2K collaboration has started the second phase of T2K requiring the Near Detector (ND280) Upgrade with a significant reduction of systematic uncertainties with respect to what is currently available. One of the key sub-detectors of upgraded ND280 is the Super Fine Grained Detector (Super-FGD) which has an innovative configuration of fine-grained fully active plastic scintillator cubes. The cubes’ size is 1 × 1 × 1 cm and the active part of Super-FGD is 182 × 192 × 56 cubes in dimension. These cubes are optically independent and read out along three orthogonal directions by wavelength shifting (WLS) fibers connected with Multi-Pixel Photon Counter (MPPC) totalling more than 56k channels. The new configuration of Super-FGD provides 3D reconstruction, full polar angle acceptance and a much lower proton tracking threshold. Furthermore, neutron tagging capabilities in addition to precision timing information will allow the upgraded detector to estimate neutron kinematics from neutrino interactions. All the features above have put many requirements for read-out electronic systems such as a large number of channels, a large dynamic range (from ~0.5 p.e up to 1500p.e), and a time resolution of sub-ns. These tasks are achievable thanks to the Front-End Board (FEB) where its electronics architecture revolves around the utilization of the Cherenkov Imaging Telescope Integrated Read Out Chip (CITIROC). Each FEB can read 256 channels and there is more than 200 FEB in total. In this poster, we will briefly present the Super-FGD and its expected performance then focus on characterizing the architecture of the FEB, together with a summary of its performance test series before mass production.
Hyper-Kamiokande (Hyper-K) is a next-generation long baseline neutrino oscillation experiment designed to make precision measurements of neutrino oscillations. These measurements will have greater sensitivity to CP violation in the lepton sector than previously possible. To measure CP violation, Hyper-K will look for the appearance of electron neutrinos coming from the flavor changing oscillations of a muon neutrino beam and compare this to electron anti-neutrino appearance with a muon anti-neutrino beam. To accomplish this goal the interaction rates of electron neutrinos and antineutrinos must be well understood. An intermediate water Cherenkov detector (called IWCD) will be constructed about 1 km from the origin of the neutrino beam. It will be able to measure the electron to anti-electron neutrino cross section using intrinsic electron neutrino contamination in the Hyper-K neutrino beam. Additionally, the IWCD is designed be movable between different off-axis angles from the primary neutrino beam direction, sampling different neutrino flux spectra as it does so. The neutrino cross section will then be measured at different neutrino energy spectra to constrain the relationship between the observed lepton and the true neutrino energy. The IWCD is carefully designed to control the backgrounds to these measurements, including those from particles produced in interactions between the neutrino beam and the material outside the detector. This poster focuses on the physics goals of IWCD and the simulation work to understand the backgrounds and how they influence the design of the detector.
KM3NeT is a deep-sea research infrastructure composed of two water-Cherenkov neutrino telescopes under construction in the Mediterranean Sea: ARCA (Italy), designed to identify and study TeV-PeV astrophysical neutrino sources, and ORCA (France), aiming at studying the intrinsic properties of neutrinos in the few-GeV range. Despite their different primary goals, both telescopes can be used to perform neutrino astronomy across an energy spectrum ranging from a few MeV to a few PeV, owing to the complementary energy ranges they are optimised for. Real-time multi-messenger searches are a key aspect of the KM3NeT program. These searches aim at combining information from complementary cosmic messengers, simultaneously measured by different observatories, in order to study transient phenomena. In this respect, the real-time distribution of alerts when potentially interesting events are detected can enhance the discovery potential of transient sources and refine the localization of poorly localized triggers, such as gravitational waves. In this context, the KM3NeT real-time analysis framework is continuously reconstructing all ARCA and ORCA events, performing core-collapse supernova analyses and searching for spatial and temporal coincidences with alerts received from other operating multi-messenger instruments. The definition of a sample of interesting events to send alerts to the external multi-messenger community is still in progress. We present the current status of the KM3NeT real-time analysis framework.
The MAJORANA DEMONSTRATOR concluded its search for neutrinoless double-beta decay in $^{76}$Ge in 2021. The experiment operated an array of up to 40.4 kg of p-type point contact high-purity germanium detectors, 29.7 kg of which were isotopically enriched in $^{76}$Ge. The experiment is also searching for double-beta decay of $^{76}$Ge to excited states of $^{76}$Se. Six possible decay modes exist, each of which produce events spanning multiple detectors that can be separated from backgrounds. The DEMONSTRATOR previously set world-leading limits in the range of $(0.75-4.0)\times10^{24}$ yrs (90% C.I.) on the various decay modes of $^{76}$Ge. Since then, the DEMONSTRATOR has collected over twice as much exposure, and several improvements have been implemented to the analysis techniques. This poster will present the MAJORANA DEMONSTRATOR's search for double-beta decay of $^{76}$Ge to excited states of $^{76}$Se.
This material is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics and Nuclear Physics Programs of the National Science Foundation, and the Sanford Underground Research Facility.
The FASER experiment is an experiment at the large hadron collider (LHC) measuring neutrinos and searching long-lived particles.
The proton-proton interactions at LHC produce hadrons in forward regions which decays into neutrinos.
These neutrinos are considered as a TeV neutrino beam source in our experiment.
The main uncertainty in the analysis is the neutrino flux because of uncertainty in the hadron productions.
The muons, which are produced at the same time from these hadrons, are measured at the FASER site.
The measurement of muons might have good information to reduce uncertainty in the neutrino flux. The measurement is also good for studying the characterization of the collider beamline.
In this poster, we report the measurement of muons by the FASER experiment and its prospects.
Within the DUNE next-generation neutrino oscillation experiment, the Near-Detector complex has the main aim of constraining systematic uncertainties, in order to allow precise oscillation measurements. The SAND detector is one of the three components of the Near Detector complex. Its aim is to monitor the neutrino beam from an on-axis position and carry out neutrino cross section measurements on different target nuclei. SAND will leverage a $0.6$ T superconducting magnet and a lead-scintillator fiber electromagnetic calorimeter. The inner magnetized volume of SAND will host a low-density tracker based on Straw Tubes (STT) and thin ($1-2\%$ $X_0$) passive target planes of various materials, capable of combining a relatively large mass (about 5 t) with high spatial and momentum resolution. Using alternating carbon and $\text{CH}_2$ targets, the STT will provide a high-statistics $\nu(\bar{\nu})-\text{H}$ CC ("solid hydrogen") interaction sample. This poster will present the physics program of the SAND tracker and the current status of the design and analysis activities, together with the R&D on small scale prototypes.
The SNO+ experiment is now preparing for the deployment of Te within the scintillator using a novel chemical loading technique, thereby enabling a $0\nu\beta\beta$ search using $^{130}\mathrm{Te}$. Numerous underground chemical purification plants have been commissioned to ensure that this technique is carried out with expected purification efficiency, stability, and process performance. This poster will discuss the status of the Te deployment programme, as well as results from the initial test runs of the Te process plant capabilities.
While cosmic rays were first discovered over a century ago, the source of the most extreme energy components remains unknown. Next-generation neutrino telescopes with substantially improved sensitivity are required to pinpoint the sources of the diffuse astrophysical neutrino flux detected by IceCube. The TRopIcal DEep-sea Neutrino Telescope (TRIDENT) will instrument ~8km^3 of seawater with optical detection modules ~3.5km deep in the South China Sea. With the use of advanced photon-detection technology and large dimensions, TRIDENT expects to observe the IceCube steady source candidate NGC 1068 at 5σ within one year of operation. This degree of sensitivity will open a new domain for the diagnosis of the origin of cosmic rays and probe for fundamental physics over astronomical baselines. Presented here are the experiment's design, status and prospects, where a pilot project of ten strings for a technology demonstration is scheduled for 2026.
SuperNEMO is searching for the hypothesised lepton-number-violating neutrinoless double-beta decay (0νββ) process. Our unique NEMO-3-style tracker-calorimeter detector tracks individual particle trajectories and energies. This enables powerful background rejection and detailed studies of Standard Model (2νββ) decay. By studying electron and photon energies and relative trajectories, SuperNEMO will investigate nuclear processes hidden to other technologies, such as decays to excited nuclear states, and will constrain the axial coupling constant, gA. By precisely measuring 2νββ observables we will seek beyond-the-Standard-Model effects like exotic 0νββ modes, Lorentz-violating decays and bosonic neutrino processes.
The SuperNEMO Demonstrator at LSM, France has a 6.1kg Se-82 ββ source, and is taking background data vital to isolate future signals. It is calibrated with a Bi-207 source deployment system. Shielding, composed of layers protecting detector against external photons and neutrons, is now in construction. The ultimate goal of SuperNEMO is to perform a background-free measurement in ROI of 0vββ for Se-82. The ββ data-taking is expected to start in 2024.
TRIDENT is a future, next-generation neutrino telescope to be built in the South China Sea, designed to discover astrophysical neutrino sources and probe fundamental physics over astronomical distances. An optimal trigger and data acquisition (TDAQ) system is needed to ensure events of interest are recorded with high efficiency, while also minimizing the rate of backgrounds during data transmission. For example, radiation from naturally occurring 40K decays in seawater creates a large background that would dominate TRIDENT's data bandwidth. A carefully crafted TDAQ system built upon optical detection modules with a multi-channel PMT design can be used to strongly mitigate this effect. TRIDENT's phase-I detector, a pilot array consisting of ten strings, will offer an excellent opportunity to commission the needed technologies for the future full TRIDENT array. This poster describes the design of the TDAQ system for TRIDENT phase-I and presents preliminary evaluations of a lab-built TDAQ prototype.
From indirect observations of the universe, we know that at least 80 % of all matter is made of galactic dark matter. As a minimal extension to the standard model of particle physics, the so-called sterile neutrinos in the keV mass range pose a viable candidate for dark matter. One way to search for these sterile neutrinos in a laboratory-based experiment is via tritium beta decay. A sterile neutrino with a mass of up to 18.6 keV would lead to a spectral shape distortion in the decay spectrum. A high-precision measurement of the entire decay spectrum with more than $10^{16}$ collected electrons is required to search for this shape distortion on the parts-per-million level. This can be achieved with the high electron rates provided by the ultra-luminous tritium source of the Karlsruhe Tritium Neutrino (KATRIN) experiment. A novel multi-pixel silicon drift detector (SDD) and readout system, called the TRISTAN detector, is currently being designed to upgrade the KATRIN detector system and extend its measurement range to search for keV-scale sterile neutrinos. The new detector system itself is segmented into 9 identical detector modules, each hosting a monolithic SDD with 166 independent pixels. To resolve the spectral shape distortion of a sterile neutrino signal, the detector system is designed to provide an excellent energy resolution of 300 eV (FWHM) at 20 keV and a low energy threshold of 2 keV.
This poster will give an overview of the current status of the TRISTAN detector system and the first characterization measurement results obtained with the 166-pixel modules.
This project has received funding from the European Research Council (ERC) under the European Union Horizon 2020 research and innovation program (grant agreement no. 852845).
The T2K experiment has worked for over a decade using ND280 as its near detector. In recent years, T2K has been upgraded to increase its beam power, upgrade ND280 and install a second near detector: WAGASCI-BabyMIND (WGBM). WGBM is composed of both plastic and water segmented trackers and muon range detectors, including the BabyMIND magnetized detector. WGBM is located beneath ND280, and is exposed to a different off-axis angle, thus being subjected to a significantly different neutrino energy spectrum. The presence of both plastic and water in ND280 and WGBM, combined with the different energy flux, provides an additional handle on the flux and cross-section modeling uncertainties, thereby increasing the sensitivity of T2K in its neutrino oscillation measurements. This poster describes the WGBM detector, the status of its ongoing physics measurements, and its expected role in the upgraded T2K experiment.
The Intermediate Water Cherenkov Detector (IWCD) will serve as a near detector for the Hyper-Kamiokande (Hyper-K) experiment. The IWCD will be used to measure and study neutrino interactions approximately 1 km downstream of the production point, where the oscillation effect is negligible. The multi-PMT (mPMT) photosensor has been developed for use in the IWCD detector due to its better timing and spatial resolution compared to the Super-K or Hyper-K 50-cm diameter PMTs. This will facilitate precise event reconstruction in the small-scale detector like the IWCD. To validate the performance of the mPMTs and event reconstruction using mPMTs in a small water Cherenkov detector, we are currently in the process of constructing a ~40-ton scale Water Cherenkov Test Experiment (WCTE) as a prototype for IWCD, with plans for operation in late 2024. The WCTE will operate in the CERN East Area T9 beam line with low momentum charged particle fluxes. The WCTE has a tank with a height and diameter of ~4 m, with the capacity to house 100 mPMT modules during operation. These mPMT modules are constructed using nineteen 3-inch PMTs arranged in a semicircle inside a water-tight vessel. The WCTE will also focus on refining the calibration system to achieve accurate particle reconstruction, a critical factor in optimizing the IWCD's performance. Additionally, the WCTE will conduct in-depth investigations into key physics processes, such as charge leptons and pion scattering, electron/gamma separation, and neutron tagging. We are currently developing an accurate mPMT simulation within the GEANT4 framework to understand the measurements taken by mPMTs. The goal of this presentation is to provide detailed information on the WCTE detector design, including a novel assembly procedure developed for building the mPMT modules, a concise overview of their mechanical and electronic components, and the calibration hardware. We will also report on the simulation as well as the crucial physics program.
The TINY (Two Isotopes for Neutrinoless double beta decaY search) experiment aims to investigate neutrinoless double beta decay (0n2b) using the $^{96}$Zr and $^{150}$Nd isotopes. Both of them possess the crucial advantage of very high transition energy for the 0n2b process, which would allow the experimenters to obtain a higher sensitivity to the effective Majorana mass compared to other isotope candidates. However, those isotopes are not the focus for large experiments due to the unavailability of a suitable scalable detector technology.
TINY project is focused on the development of a “source=detector” technology for these two candidates. Bolometric detectors have proven their applicability for 0n2b decay searches, utilizing various absorber compounds and isotope candidates, as was done in CUORE (TeO$_2$ absorber), CUPID-Mo, AMoRe (Li$_2$MoO$_4$), CUPID-0 (ZnSe). These experiments have demonstrated high energy resolution and the possibility of active particle identification with scintillating cryogenic bolometers.
Following this approach, TINY will investigate dielectric absorbers containing the isotopes of interest: $^{96}$Zr will be embedded into ZrO$_2$ crystals, measured with thermal sensors, and coupled to auxiliary light detectors for active alpha particles rejection. $^{150}$Nd will be studied with magnetic NdGaO$_{3}$ absorbers and athermal phonon sensors. Particle identification will be achieved via pulse shape discrimination.
The successful R&D would provide technology for Zr- and Nd- -based bolometric detectors with high performance, which will be measured in the TINY pilot experiment. It will consist of a few kg scale underground demonstrator and will be able to set the best limits worldwide on the 0n2b half-lives for both $^{96}$Zr and $^{150}$Nd isotopes thanks to high efficiency and energy resolution.
T2K (Tokai to Kamioka) is a long-baseline neutrino oscillation experiment that has taken data since 2010. After having obtained the first hints of CP violation in the leptonic sector, it has entered a second phase with an upgrade of its accelerator beam line and suite of near detectors. Among the different elements of this upgrade, two High-Angle Time Projection Chambers (HA-TPC) were installed. Each endplate of these HA-TPC is equipped with Encapsulated Resistive Anode MicroMegas (ERAM). This innovative technology owes its originality to the use of a layer of insulator and a layer of glue to engender charge spreading on the detector's pads. Several test beam and cosmics data taking campaigns have validated these HA-TPC and showed an even better spatial resolution than the Bulk MicroMegas technology that equips the vertical TPC already present for the first phase of T2K. New reconstruction algorithms had to be developed to fully exploit the capabilities of these detectors. These are presented in this poster together with the first performances they allowed to obtain.
The ICARUS collaboration has employed the 760-ton T600 liquid argon TPC detector in a successful three-year physics run at the underground LNGS laboratory, performing a sensitive search for LSND-like anomalous $\nu_e$ appearance in the CERN Neutrino to Gran Sasso beam, which contributed to the constraints on the allowed neutrino oscillation parameters to a narrow region around 1 eV$^2$. After a significant overhaul at CERN, the T600 detector has been installed at Fermilab. The detector commissioning phase lasted until June 2022, then ICARUS moved to data taking for neutrino oscillation physics collecting events from the Booster Neutrino Beam (BNB) and the Neutrinos at the Main Injector (NuMI) beam off-axis. The initial experiment goals are to either confirm or refute the claim by Neutrino-4 short-baseline reactor experiment, perform measurements of neutrino cross sections with the NuMI beam and several Beyond Standard Model searches. Then, ICARUS will jointly search for evidence of sterile neutrinos with the Short-Baseline Near Detector (SBND). In this contribution, we discuss recent changes to the standard TPC event reconstruction that uses Pandora, a pattern recognition software common to liquid argon-based detectors. In particular, we performed a new training of the Boosted Decision Tree (BDT) employed to separate track-like and shower-like reconstructed particles using Monte Carlo simulations of neutrino events from BNB in ICARUS. We compare the discrimination capabilities of the old and new BDT training and discuss further improvements of this algorithm.
Interest in the β-decay endpoint of atomic tritium is reaching new highs. The absolute mass of the neutrino is not yet known - PTOLEMY will soon join KATRIN and Project-8 in the fray. The PTOLEMY concept relies upon a cyclotron radiation emission spectroscopy trigger and a non-destructive tracking system. The TRItium-endpoint From 𝒪(fW) Radio-frequency Cyclotron Emissions group is leading the R&D in this vein. The development of radio-frequency cavities for the simultaneous transport of endpoint electrons and the extraction of their kinematic information is essential in providing a fast online trigger and precise energy-loss corrections. The cryogenic low-noise, high-frequency analogue electronics combined with FPGA-based front-end analysis capabilities will provide the PTOLEMY demonstrator with its CRES readout and a testbed for further R&D at the Gran Sasso National Laboratory for the full CνB detector.
Trinity, an imaging atmospheric Cherenkov telescope (IACT) observatory, is proposed for detecting very high energy (VHE) and ultra-high energy (UHE) cosmic neutrinos.
It is designed to detect Earth-skimming tau-neutrinos, transforming into tauons which emerge in the atmosphere and decay producing air showers. Currently, Trinity is in its Demonstrator phase featuring a 0.75 m² mirror area telescope with a 5° x 5° FoV, deployed at Frisco Peak, Utah, and it promises to be the most sensitive VHE-neutrino detector for sources, pointed at NGC 1068 and TXS 0506+56. The Demonstrator became operational and started data-taking since October 3rd, 2023. This presentation highlights the Trinity Demonstrator's status, showcasing initial data acquisition results, stability, remote operation, background assessment, atmospheric monitoring, and data analysis development.
The KATRIN experiment is designed to measure the effective mass of the electron anti-neutrino by studying the high-energy end of the tritium β-decay spectrum. After completing the neutrino mass campaigns, KATRIN plans to search for keV-scale sterile neutrinos. For this purpose, a novel detector system called TRISTAN is under development. The detector will consist of about 1500 Silicon Drift Detector (SDD) pixels, arranged in so-called detector modules. The SDD modules are now in production, and the commissioning of the detector is expected to begin in 2026. Thanks to the high tritium source activity of KATRIN, a statistical sensitivity at the level of sin$^{2}$θ < 10$^{-6}$ can be achieved. To achieve a high sensitivity, an accurate modeling of the expected spectrum accounting for all systematic effects of the experimental setup is required.
In this poster, we will present the ongoing efforts to model the expected tritium spectrum at the detector. The dominant systematic effects as well as the expected sensitivity of the KATRIN experiment to keV sterile neutrinos will be reported.
In this poster, a microscopic quantum mechanical model for
gravitationally induced decoherence in the context of neutrino
oscillations is presented. The focus is on the comparison with existing
phenomenological models and the physical interpretation of the
decoherence parameters in such models. The results show that for
neutrino oscillations in vacuum gravitationally induced decoherence can
be matched with phenomenological models with decoherence parameters of a
specific form. When matter effects are included, the decoherence
parameters show a dependence on matter effects, which vary in the
different layers of the Earth, that can be explained with the form of
the coupling between neutrinos and the gravitational wave environment
inspired by linearised gravity. Consequently, in the case of neutrino
oscillations in matter, the microscopic model does not agree with many
existing phenomenological models that assume constant decoherence
parameters in matter, and their existing bounds cannot be used to
further constrain the model considered here. The probabilities for
neutrino oscillations with constant and varying decoherence parameters
are compared and it is shown that the deviations can be up to 10%.
Furthermore, the quantum mechanical model is compared with master
equations derived from a field-theoretic model based on linearised gravity.
The detection of high-energy astrophysical neutrinos by IceCube has opened a new window on our Universe. While IceCube has measured the flux of these neutrinos at energies up to several PeV, much remains to be discovered regarding their origin and nature. Currently, the discovery of point sources of neutrinos is hindered by atmospheric neutrino backgrounds; likewise, astrophysical neutrino flavor ratio measurements are limited by the difficulty of discriminating between electron and tau neutrinos. TAMBO is a next-generation neutrino telescope specifically designed to detect tau neutrinos in the 1-100 PeV energy range. This tau neutrino specificity enables a nearly background-free identification of astrophysical neutrino sources, as well as tests of the flavor ratio of astrophysical neutrinos. TAMBO will comprise an array of water Cherenkov and plastic scintillator detectors deployed on the face of the Colca Canyon in the Peruvian Andes, with its unique geometry facilitating the high-purity measurement of astrophysical tau neutrinos. In this poster, I will present the prospects of TAMBO in the context of next-generation neutrino observatories and provide an overview of its current status.
The Tokai-to-Kamioka (T2K) long-baseline neutrino oscillation experiment entered a new phase with enhanced neutrino beams. J-PARC neutrino beam is produced from decayed pions and kaon created by interaction with proton beams at a graphite target. To provide a higher intensity accompanying the J-PARC main ring accelerator upgrade, the J-PARC Neutrino beamline group upgraded and exchanged beamline instruments like beam monitors, electromagnetic horns and target. Beam commissioning was started in November 2023 after the long shutdown for the upgrade works in 2021-2022. We have successfully achieved a record beam power of about 760 kW, which is an increase of more than 40% compared to that before the upgrade and greater than the initial design beam power. While supplying the beam for the T2K experiment, we aim for further increase of the beam power to 1.3 MW. It is also a key in the next generation of neutrino research, Hyper-Kamiokande, toward unraveling the mystery of the missing antimatter from our universe. In this poster, we present our successful achievement of a record beam power with the upgraded J-PARC neutrino beamline and future prospects toward the realization of higher beam power.
KM3NeT is a European research infrastructure building second-generation neutrino telescopes in the Mediterranean Sea, comprising in its final configuration a network of detectors that will cover more than one cubic kilometre of deep seawater. KM3NeT/ARCA is part of the KM3NeT research infrastructure and focuses on the detection of high energy neutrinos (>TeV) from astrophysical sources. The KM3NeT/ARCA detection units are deployed offshore Capo Passero, Italy at a depth of 3500 m, delivering data as the construction of the detector is ongoing. In this contribution the results of an all-flavour search for diffuse astrophysical neutrino fluxes, using the full dataset obtained with the first KM3NeT/ARCA configurations of appreciable instrumented volume, namely ARCA6 (6 detection units), ARCA8, ARCA19 and ARCA21, will be presented.
Two cases are considered: an all-sky diffuse flux and a flux coming from the Galactic Ridge,
namely |b| < 2◦ and |l| < 30◦, in Galactic coordinates. Recently, strong evidence of a diffuse
neutrino emission from the Galactic plane has been reported by the IceCube Collaboration.
However, the angular resolution of the exploited data set allows open questions about the origin of this flux, especially regarding the relative contribution of unresolved sources. KM3NeT detectors are located in the Northern hemisphere, fully complementing the field of view of the IceCube neutrino telescope, and having the possibility to observe the centre of our Galaxy for most of the time with outstanding angular resolution, exploiting track-like upward-going events.
Machine learning techniques for the event selection and a bayesian method for the statistical analysis will be presented.
The DsTau (NA65) experiment at CERN was proposed to measure an inclusive differential cross-section of Ds production, and its decay branching ratios in p-A interactions. The DsTau detector is based on the nuclear emulsion technique providing an excellent spatial resolution for detecting short-lived particles like charmed hadrons. The first results of the analysis of the pilot-run data are presented. The accuracy of the proton interaction vertex reconstruction is reported. A high precision in vertex reconstruction allows one to measure the proton interaction length and charged particle multiplicities accurately in a high-track density environment. The measured data have been compared with several Monte Carlo event generators in terms of multiplicity and angular distribution of charged particles. The results presented in this study can be used to validate event generators of p-A interactions.
The identification of cosmic objects emitting high energy neutrinos provides new insights about the Universe and its active sources. Although cosmic neutrinos have been observed by the IceCube Neutrino Observatory, the sources of these neutrinos still remain unknown. The KM3NeT/ARCA detector for Astroparticle Research with Cosmics in the Abyss, is currently being built in the Mediterranean Sea at about 3500 m depth and 100 km off the Sicilian coast, near Capo Passero. To record the neutrino induced Cherenkov light, on its final configuration the detector will consist of >4000 light sensitive optical modules with 31 photomultiplier tubes each, distributed over 230 detection units. The detector will instrument a volume of a cubic kilometre of seawater. KM3NeT has a view of the sky complementary to IceCube, and is sensitive to neutrinos across a wide range of energies. The results of a binned all-sky scan are presented, as well as a binned time-integrated point source and an extended source searches in the direction of a list of preselected candidate sources. The galactic and extragalactic candidates are selected based on GeV – EeV information from other neutrino experiments, cosmic ray observatories as well as optical measurements. For all presented analyses, KM3NeT/ARCA data from May 2021 until September 2023 taken with an evolving detector geometry up to 21 detection units is used.
Chair: Francis Halzen
The Pierre Auger Observatory, originally designed for the detection of ultra-high-energy cosmic rays, has also the capability to detect neutrinos with energies above 100 PeV. The identification, through the special characteristics of highly inclined showers, is efficiently performed for neutrinos of all flavours. This presentation reviews the status of the neutrino search at the Observatory. Upper limits on the neutrino flux from diffuse and point-like sources have been established, placing constraints on models of neutrino production at EeV energies and on the properties of the sources of ultra-high-energy cosmic rays. High sensitivity in search for transient sources has also been achieved.
Chair: Kyle Leach
The KArlsruhe TRItium Neutrino experiment (KATRIN) is searching for the signature of the neutrino mass in the endpoint region of the tritium beta-decay spectrum. KATRIN combines a high-intensity gaseous molecular tritium source with a high-resolution electrostatic spectrometer with magnetic adiabatic collimation which allowed KATRIN to reach a sub-eV sensitivity to the neutrino mass and to set an upper limit of 0.8 eV/c^2 (90% CL) already with the first 5% of the total expected data.
This talk discusses the analysis of a larger dataset with 25% of the KATRIN data and improvements in terms of signal-to-background ratio and systematics, and gives an outlook on the future prospects of KATRIN.
The first proposal of the neutrino idea is about to turn a century old. In this lecture, we recall the fundamental advances that occurred soon after, in the era of modelling the atomic nucleus. We discuss the subsequent modifications and developments of the neutrino concept, which shaped modern thinking and prepared for observational advances. We retrace a journey through history, organised in six stages, focusing in particular on the initial ones:
1. Early 1930s. Pauli's neutrino and its significance.
2. Fermi 1933-34: The first beta-ray and neutrino theory. Conceptual and formal foundations, implications. Electron capture.
3. Majorana 1937: The modern understanding of fermions. A new concept of neutrino.
4. From muons to families. The numbers of leptons. Nature of weak interactions and the neutrino. The standard model and its failure.
5. Pontecorvo & Sakata's winning approach to neutrino mass.
6. The part that remains to be written: How to observe the absolute mass of the neutrino? What is its nature?
Chair: Kate Scholberg
The increasing precision of cosmological observations has opened a new window for studying neutrinos.
After reviewing current cosmological constraints on neutrino properties, I will show the potential of forthcoming large-scale structure data from the ESA Euclid mission to detect the neutrino mass sum and provide insights into the existence of light particles beyond the Standard Model.
In its first year of operation, the Dark Energy Spectroscopic Instrument (DESI) has measured the spectra of more than 6 million extragalactic objects. These spectra enable precision measurements of the large-scale distribution of matter in the Universe. One of the key measurements made by DESI is that of the baryon acoustic oscillation scale, which, in combination with measurements of the cosmic microwave background, lead to the strongest current constraints on the sum of neutrino masses and the effective number of neutrino species. In this talk, I will give an overview of the DESI experiment, present its Year 1 cosmological results, and discuss their implications for neutrino physics. I will also give an outlook on other measurements that DESI could make to further strengthen these bounds.
In this talk I review the meaning of cosmological bounds on two important quantities, the effective number of relativistic species Neff and the sum of neutrino masses, and their relation with fundamental neutrino properties. I discuss several non-standard scenarios where Neff can be significantly altered (much larger or much smaller than 3), and also scenarios which barely change its value. Concerning the sum of neutrino masses, I will show how it is possible to avoid cosmological bounds with neutrino decay or time-dependent masses, in order to reconcile cosmological observations with neutrino oscillation constraints.
Chair: Yusuke Koshio
Following a long history of discoveries, the field of solar neutrinos maintains the dual interest of providing a way to probe the mechanism of the Sun's burning, as well as an intense source of neutrinos to test the standard oscillations paradigm.
This talk focuses on recent results on 8B solar neutrinos from the Super-Kamiokande and SNO+ experiments, and outlines the prospects for new measurements of the wider spectrum with upcoming experiments. In fact, a combination of massive new detectors aimed at beam or reactor neutrino oscillations (JUNO, HK, DUNE), and the development of new technologies in liquid scintillator experiments (JNE, THEIA, CLOUD) has the potential to go much beyond the current reach.
There are several unanswered fundamental questions about our planet, particularly concerning the deep Earth, from where we lack direct rock samples. Today, thanks to advances in particle detection techniques, geoneutrinos — antineutrinos emitted during the decays of long-lived radioactive elements inside the Earth — can be detected and used as a unique tool to study our planet. Geoneutrinos from the 238-Uranium and 232-Thorium radioactive chains, with energies above 1.8 MeV, have been measured by the KamLAND experiment in Japan and the Borexino experiment in Italy, utilizing the charge-current inverse-beta decay interaction on protons. Both detectors are located underground and feature large-volume liquid scintillator targets. The most relevant backgrounds to geoneutrino measurement include reactor antineutrinos, residual muon flux, and the intrinsic radioactivity of the detector. Both experiments achieved similar precision in geoneutrino signal measurement, with a range of 15 to 18%, and confirmed a general consistency of the measured signal with geological expectations. Due to their different geological settings and geographical locations, their results are complementary. This talk will introduce the importance of geoneutrinos to geoscience, provide an overview of the latest measurements, and offer a brief outlook on this interdisciplinary field. SNO+ in Canada is presenting its first full-scintillator antineutrino spectrum at Neutrino 2024, which includes evidence for the detection of geoneutrinos. JUNO, the next-generation detector in China, is expected to collect the equivalent of the existing world geoneutrino statistics in less than a year and is nearing completion. Measurements from multiple locations around the globe are about to mark a new chapter in geoneutrino research, providing important insights about our planet.
Chair: Marcos Dracos
The interaction of cosmic rays with the atmosphere generates a neutrino flux spanning from 10 MeV to over 10 TeV, traveling through baselines from ~10 km to ~1000 km. This creates an ideal environment for testing neutrino evolution. Atmospheric neutrinos have been crucial in discovering neutrino oscillations and continue to advance our understanding. In this talk, we assess the sensitivity of current and upcoming atmospheric neutrino experiments within the standard three-flavor oscillation framework. We analyze shared systematic uncertainties and explore the potential of a joint analysis to resolve major uncertainties in the three-neutrino mixing scenario. Our results indicate that the octant of θ23 can be resolved at the 99% confidence level, and the neutrino mass ordering determined with over 5σ significance. We also find that certain values of the CP-violating phase can be excluded with more than 3σ significance.
The IceCube Neutrino Observatory is a cubic-kilometre Cherenkov neutrino telescope deep in the glacial ice at the geographic South Pole. Thanks to its low energy extension, DeepCore, the instrument can observe atmospheric neutrinos as low as 5~GeV, going up to hundreds of TeV with
the full array. This wide energy flux comes from all directions in the sky, and is modulated by oscillations driven by $\Delta m^2_{atm}$. With $O$(100k) atmospheric neutrinos detected every year, IceCube DeepCore has unprecedented statistical power to measure atmospheric
neutrino oscillations, as well as to search for exotic oscillations and other non-standard phenomena that might affect neutrinos at energies that cannot be currently reached by accelerators. In this talk I will review the results obtained by IceCube over the last decade, including the most recent results on neutrino oscillations, and will show the expected impact of additional instrumentation that will be deployed in the near future.
A new generation of atmospheric neutrino detectors will become operational within the next few years. With instrumented water/ice masses ranging from 0.2 Mtons to several Mtons they will accumulate several 100,000 neutrino events per year. This wealth of data accompanied by improvements of systematic uncertainties will allow to perform competitive precision measurements in the GeV energy range before the end of the decade. The determination of the hitherto unknown neutrino mass ordering can be addressed as well as a precision measurement of the neutrino oscillation parameters dm2_31 and th_23. Further, these next generation atmospheric neutrino detectors will accumulate the world largest sample of tau neutrino interactions. This will on one hand allow to determine the tau neutrino cross section close to its kinematic threshold and can serve on the other hand as a portal for various beyond Standard Model searches.
Chair: Artur Ankowski
Chair: Jelena Maricic
Chair: Deborah Harris
MicroBooNE currently possesses the world's largest neutrino-argon scattering data set, with twenty measurements already publicly available and many more ongoing analyses studying a wide variety of interaction processes. This talk provides an overview of MicroBooNE's most recent results on neutrino interactions. These include investigations of multi-differential inclusive channels with and without detected protons, exclusive pionless topologies, analyses with pion final states, rare processes, and novel neutron detection techniques. These measurements provide invaluable datasets for constraining backgrounds and improving the modeling of neutrino scattering for MicroBooNE and the broader LArTPC neutrino physics programs, including DUNE.
The NP06/ENUBET experiment concluded its ERC funded R&D program demonstrating that the monitoring of charged leptons from meson decays in an instrumented decay tunnel can constrain the systematics on the resulting neutrino flux to 1%, opening the way for a cross section measurement with unprecedented precision. The two milestones of this phase, the end-to-end simulation of a site independent beamline optimized for the DUNE energy range and the testbeam characterization of a large scale prototype of the tunnel instrumentation, will be discussed. We will also present studies for a site dependent implementation at CERN carried out in the framework of Physics Beyond Colliders. This work is based on a more efficient version of the beamline able to cover the HK energy region as well and will include radioprotection and civil engineering studies, with the goal of proposing a cross section experiment in the North Area with the two protoDUNEs as neutrino detectors, to be run after CERN LS3.
Future long-baseline neutrino experiments seek unprecedented precision in measuring oscillation parameters. Achieving this requires accurate characterization of incoming neutrino energy, reliant on robust nuclear and cross-section models embedded in event generators. External data plays a crucial role in constructing these models. The distinctive characteristics of electron scattering data provide the most accurate inputs, thanks to high statistics and a well-known monochromatic beam, offering a complementary picture since electrons and neutrino share the vector part of their interaction with the nuclear, which has the same nuclear effects.
Most of the data available is inclusive and limited to specific targets, energies and angles. The Electrons for Neutrinos collaboration (e4ν) exploits data from two large acceptance spectrometers, CLAS6 and CLAS12. They employ 1-11 GeV beams with targets ranging from hydrogen and deuterium through carbon and argon to lead.
In this talk, we unveil new inclusive cross-sections on argon at all angles from 10 to 35, semi-inclusive (e, e′π) cross sections on deuterium and exclusive carbon pion-production and two-nucleon knockout cross sections. This new data, covering a wide range of energies, targets, angles, and final state topologies, will uniquely constrain event generators.
Chair: Yasaman Farzan
Chair: Carlos Arguelles
The recent discoveries of high-energy astrophysical neutrinos and gravitational waves have opened new windows of exploration to the Universe. Neutrinos can escape dense environments from where photons can not reach us and travel undeflected through the Universe. In combination with measurements of electromagnetic radiation, neutrinos can help to solve long-standing problems in astrophysics and probe physics that plays a role at extreme conditions that otherwise are hardly accessible to laboratory experiments. For example, MeV neutrinos play a crucial role to alert electromagnetic observatories about the detection of a Galactic supernova, while TeV-PeV neutrinos have the potential to reveal the origin of cosmic rays. This talk will review the status of multi-messenger searches, including neutrinos.
Neutrino cross-sections are often extracted purely in terms of lepton kinematics. In recent years more detailed analyses have been developed that additionally make use of kinematics in the hadronic system, which has proven very successful. However, even with new detector technologies of unparalleled precision, pattern recognition and reconstruction algorithms still require particle energies above a given detection threshold. Calorimetric variables directly inferred from the total visible energy created in scintillation or ionisation processes in the detector material provide an alternative handle on the kinematics in the hadronic system and do not rely on a successful kinematic reconstruction of the hadron track. In quasi-elastic-like topologies the visible energy in the hadronic system corresponds to the sum of proton kinetic energies ($\Sigma T_p$), a variable explored via a calorimetric approach in a recent publication by the Miner$\nu$a collaboration. This poster will present an on-going cross-section analysis conducted at the upgraded ND280 detector within the T2K collaboration. The cross-section of $\nu_\mu$CC interactions without pions in the final state will be extracted in terms of muon kinematics and calorimetric variables. Particular focus will be brought on biases in the reconstruction of hadronic energy from visible energy due to material effects like Birks' quenching when particle multiplicities are unknown.
The China Jinping Underground Laboratory (CJPL) is an excellent location for studying solar, geo- and supernova neutrinos. As an early stage of the Jinping Neutrino Experiment (JNE), we have been studying the performance of a 1-ton liquid prototype neutrino detector at CJPL-I. We aim to improve its electronics system and photomultiplier tubes (PMTs) to explore its potential capabilities further. We have developed a new electronic system with higher resolution, greater bandwidth, and faster storage speed. We plan to replace the current Hamamatsu 8-inch PMTs with North Night Vision (China) 8-inch MCP-PMTs and increase the number of PMTs from 30 to 60. These new technologies will be used for the future 500-ton neutrino detector at CJPL. The poster will present the upgrade plan, equipment, progress, and physical improvements of the 1-ton neutrino detector.
The Taishan Antineutrino Observatory (TAO) aims to measure the fine structure in the reactor antineutrino spectrum with an unprecedented energy resolution of better than 2% at 1 MeV. Its primary goal is to provide a reference spectrum for JUNO, thereby enhancing its sensitivity for determining neutrino mass ordering. The precise spectrum also serves as a benchmark to verify the nuclear database and promote related research in nuclear physics. The TAO detector combines cutting-edge technologies in liquid scintillation and solid-state photon sensors to achieve the desired performance. About 10 m2 of SiPMs, covering 94% of the area, will be deployed to efficiently collect scintillation light, yielding a light yield of ~4000 p.e./MeV. The TAO detector will operate at -50 ℃ to suppress the dark count rate of SiPMs, with the SiPM performance being a critical factor influencing the detector's overall performance. This poster will report the mass testing results obtained at -50 ℃ for approximately 4000 SiPM tiles (5 cm × 5 cm each), comprising around 64,000 channels. The poster will summarize key parameters, including photon detection efficiency, dark count rate, probabilities of optical cross-talk and after pulse, etc.
Hadron interaction model for light nucleus has an important roll in understanding neutrino reaction in a large neutrino detector. In Super-Kamiokande, neutral current quasi-elastic interaction (NCQE) induced by atmospheric neutrino gives 68-82% uncertainty on search for diffuse supernova neutrino background, which is caused by the uncertainty on interaction model between oxygen and high energy neutron generated by NCQE interaction.
Therefore, we performed a simulation study by comparing with newly released neutron-oxygen experimental data from E525 experiment. The result of comparison among combinations of intranuclear cascade and de-excitation model are presented in order to choose a model giving better prediction based on the experimental data.
The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose
experiment designed to determine the neutrino mass ordering and precisely measure
neutrino oscillation parameters. JUNO is the world's largest liquid scintillator detector
instrumented with 17,612 20-inch photomultiplier tubes (PMTs). It is critical to develop
an accurate optical model for the PMTs within their working media in order to describe
the photon detection efficiency (PDE) at any incident angle and photon wavelength.
This poster reports in detail how a combination of simulation and measurements were
used to establish the JUNO PMT Optical model. The model relates the PDE to the
underlying optical processes using a transfer-matrix method (TMM) thin film
calculation that depends on thicknesses and complex refractive indices of the
photocathode and anti-reflective coatings of the PMTs.
In the field of neutrino physics, with its 20 000 ton of organic liquid scintillator, JUNO (Jiangmen Underground Neutrino Observatory) will be the largest detector built of its kind. The JUNO detection medium will be a mixture of linear alkyl benzene (LAB), 2.5 g/L of PPO and 3 mg/L of bis-MSB. The main goal of JUNO is to determine the neutrino mass ordering in six years of data taking at $3\,\sigma$ level. This thanks to its high energy resolution given by the knowledge of the detection medium and an excellent optical coverage $\sim\,78\,\%$.
For this reason during these years of detector construction, there was a big effort from the collaboration to obtain the best characterisation of the JUNO liquid scintillator possible.
In this poster we want to summarise the whole measurements that will be used in the official JUNO Monte Carlo representing our best knowledge on the liquid scintillator. This is crucial for all the analysis task and in particular for the Monte Carlo based analysis for solar neutrinos.
In particular we present our measurements on the refractive index, which impacts on the light propagation and the Cherenkov light emission, crucial in the energy resolution model. We will also show our results on fluorescence time profiles which will help JUNO to identify the incident particle and to reconstruct the position of an event. The absorption length measurements, which are crucial since the huge dimension of the detector (40 meter of diameter) for the energy and position reconstruction. In the end we will show the emission spectrum measurements which strongly impact on the energy resolution.
NOvA's near detector has recorded millions of neutrino interactions in the NuMI beam at Fermilab in both neutrino-enhanced and antineutrino-enhanced beam modes. Although the beam is composed primarily of muon (anti)neutrinos, there are inherent electron neutrinos and antineutrinos in both beam modes. I will present the current status of a measurement of the $\overline{\nu}_e$ charged-current inclusive cross section in the NOvA near detector. The results will be presented as a double-differential cross section in the final-state electron energy and angle. The cross section is determined by performing a template fit of a multivariate electron (anti)neutrino identifier using a covariance matrix to account for correlations between the various beam mode, electron energy, and electron angle bins.
KATRIN (KARlsruhe TRItium Neutrino experiment) plans to perform a high-precision differential measurement of the entire tritium β spectrum to search for keV-sterile neutrinos. To sustain the very high rate, KATRIN’s detector will be upgraded with a multi-pixel Silicon Drift Detector (SDD). The new detector response must be accurately tested in laboratory conditions, and therefore an ideal electron source is needed. We developed a photoelectric-based electron gun that can go up to 20 keV and reach a rate of O($10^4$ cps) with a spot size of a few hundred micrometers. We designed and built a vacuum chamber to house this source and an SDD matrix, where the efficiency loss at the detector entrance window or at the boundaries can be probed. Furthermore, by slightly modifying the setup, backscattering coefficients and spectra of different materials can be measured by using this electron source. These data are important for the design of the new KATRIN phase and also provide a benchmark for low-energy MC simulations.
This setup is also used for the ASPECT-BET (An sdd-SPECTrometer for BETa decay studies) project, where SDDs are used to measure several allowed and forbidden β decays, with the goal of helping to find a theoretical nuclear framework able to reproduce all the measured spectra, which is mandatory for future neutrinoless double beta decay experiments and reactor oscillation experiments.
Scintillators read with a SiPM, used as a veto detector in the ASPECT-BET measurements, and a Timepix sensor, used to monitor the e-gun beam spot, are also installed in the vacuum chamber.
In this contribution, we will show the main results achieved using this setup.
In the recent past, substantial effort has been devoted to exploring flavour symmetries to solve the flavour puzzle. However, traditional flavour symmetry models proved to be quite unsatisfactory. In 2017, a new 'bottom-up' approach based on modular invariance was suggested, wherein the Yukawa couplings of the Standard Model become modular forms. Within this framework, we addressed the following question: is it possible to employ the smallest and most minimal modular group $S_3$ to construct predictive neutrino mass models? As demonstrated in our work, the answer is affirmative if we assume a certain set of guiding principles that fully exploit modular invariance.
Measurements of the $\beta^-$ spectrum of tritium give the most precise directly measured limits on neutrino mass. The Project 8 collaboration is using Cyclotron Radiation Emission Spectroscopy (CRES), a new experimental technique developed to surmount the systematic and statistical limitations of current-generation direct measurement methods to reach an electron-weighted antineutrino mass sensitivity of ${\sim}$40 meV/c$^2$. Since setting the first CRES-based neutrino mass limit in its Phase II experiment, Project 8 has been developing techniques to scale in volume and energy resolution. A new Cavity CRES Apparatus (CCA) is the first CRES detector with a resonant cavity geometry, with several expected benefits: increased signal-to-noise ratio via enhanced spontaneous emission on resonance; scalability to larger volumes; sub-eV energy resolution; event-by-event magnetic field corrections; and improved signal morphology via suppression of the Doppler effect. This apparatus is under construction at the University of Washington, with expected sub-eV energy resolution and plans for spectroscopy of both conversion electrons from Kr-83m and of electrons from a calibration electron gun.
The lithium chloride aqueous solution has great potential to be the detection medium of a novel neutrino detector for multiple purposes. The nuclide $^7$Li provides a charged-current interaction channel with a high cross-section for the MeV-scale solar electron-neutrinos, enabling measurement of the solar neutrino spectrum. Its advantages in studying the upturn effect of solar neutrino oscillation, light sterile neutrinos, and Earth matter effect are investigated in detail. Meanwhile, the contained $^{35}$Cl, $^6$Li, and $^1$H can capture the neutrons generated from inverse beta decay. This feature enables a delayed-coincidence detection for electron-antineutrinos, crucial for measurements of the neutrinos from the Earth, nuclear reactors or celestial objects. A saturated lithium chloride solution, containing 45.3%w/w salt in water, is prepared and purified for the large liquid neutrino detector. Its optical properties and the light yields are measured. The solution shows little absorption in the sensitive wavelength range of the bialkali photomultipliers. The attenuation length is evaluated to reach 50 meters at 430 nm. In addition to being a pure Cherenkov detector medium, a wavelength shifter, carbostyril 124, is added to the LiCl aqueous solution. The compatibility and the enhancement of the light yield are confirmed, enabling the development of a Cherenkov-enhanced lithium-rich detector. The experimental results prove that the salt-rich liquid detector is a practical candidate for a novel neutrino experiment.
Neutrino oscillation experiments using neutrino beams achieve high sensitivity to oscillation parameters by restricting the range of L/E values probed to be near a theoretical maximum disappearance probability. However, these experiments are insensitive to the oscillation phenomena predicted across a broad range of L/E values. Atmospheric neutrinos have energies spanning hundreds of MeV to several TeV and are detected over baselines between 15-13,000 km, covering four orders of magnitude in L/E. We present an analysis of the highest-resolution events from 6511 live-days of Super-Kamiokande atmospheric neutrino data to explore the oscillation region beyond the first muon neutrino disappearance maximum. We report prospects for measurements of neutrino oscillation parameters and a model-independent significance of multiple oscillation features in the ratio between oscillated data and the un-oscillated prediction.
The increasingly precise measurements needed to push the frontiers of neutrino physics require the construction of ever larger experiments, leading to ever more complex data to be interpreted. The JUNO next generation detector will reach a mass of 20 ktons and is expected to collect 2 PB/year of raw data to detect over 500.000 antineutrino events in 30 years of data.
The challenge is not just represented by the sheer volume of data. Such large detectors have inherent inhomogeneities, as spatial non uniformities and non linearity effects in the detector response. Other factors, such as detector coverage, detection efficiency or the incoming neutrino flux, can change in time due to failures, planned modifications to the detector or factors outside the control of the experiment.
Analysis frameworks must be able to cope with this evolution, allowing efficient processing of large numbers of events and providing flexible modelling of different detector responses. In this context, unbinned analyses have always been considered promising, but difficult to handle. They can incorporate spatial and temporal variations and characterize the detector response on an event by event basis. Their main limitation is the computational time, which scales linearly with the number of events processed.
Over the last few decades, architectures developed for other fields, such as GPUs, have found fertile ground in physics applications, leading to a huge leap in computing power. The use of these architectures targeted to parallel computing and the development of efficient and multi-threaded code can help to bridge the gap in this generational advance required to analyses in neutrino physics. This work describes the GPU implementation in Numba and CUDA of the unbinned likelihood calculation, capable of incorporating spatial and temporal information, to fit the JUNO reactor antineutrino spectrum.
The decay of radiogenic isotopes—such as uranium, thorium, and potassium—within the Earth generates radiogenic heat, driving Earth's dynamics. These isotopes also produce geo-neutrinos (anti-electron neutrinos), which serve as the only direct means of observing Earth's internal heat content. KamLAND experiment marked the world's first observation of geo-neutrinos in 2005. Since then, KamLAND has observed geo-neutrinos continuously with 1 kt liquid scintillator.
One major challenge in geo-neutrino observations is the reduction of accidental backgrounds. Although likelihood selection has traditionally been employed for this purpose, this study introduces a new method utilizing decision trees, achieving substantial improvements in background removal efficiency.
In this presentation, I will discuss the methods for background reduction using decision trees and Particle Identification (PID) employing neural networks.
Despite the incredible success and resilience of the Standard Model of particle physics, there are a few reasons to believe that it is not the final picture of all physical phenomena. Notable examples include the existence of neutrino mass and the collection of cosmological observations which comprise the case for a dark and widespread matter. While there are many experiments dedicated to tests of specific physics, the incredible abundance of theories that need investigating demands that experimentalists be highly opportunistic and leverage existing experiments for as many tests as possible. LEGEND-200 is the 200 kg phase of the LEGEND collaboration and is a low background search for neutrinoless double beta decay. On top of being one of the leading searches for neutrinoless double beta decay, LEGEND-200 can be leveraged as a platform for a wide variety of searches for physics beyond the Standard Model that go beyond neutrino mass mechanisms. Building on the success of its predecessors MAJORANA and GERDA, possible searches can include tests of fundamental symmetries, sterile neutrino models, and exotic currents in the weak interaction. This poster will provide an overview of the types of searches that LEGEND-200 can perform. By leveraging all of the existing detector systems in the experiment the collaboration can widely search for hints of physics beyond the Standard Model.
This work is supported by the U.S. DOE and the NSF, the LANL, ORNL and LBNL LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Russian RFBR; the Canadian NSERC and CFI; the LNGS, SNOLAB, and SURF facilities.
Neutrinos are proven to have non-zero masses by the observation of neutrino oscillations, while the absolute neutrino mass scale is still unknown. Cosmological observations and neutrinoless double beta decay experiments put model-dependent upper limits of the neutrino mass at sub-eV level. With a precise spectroscopy of molecular tritium beta decay spectrum near the endpoint energy, the KArlsruhe TRItium Neutrino (KATRIN) experiment sets the most stringent model-independent upper bound for the absolute neutrino mass. This poster will discuss the two analysis methods used for the first five measurement campaigns. In the frequentist approach, neutrino mass is derived by a combined fit of all measurement campaigns based on a highly optimized model calculation, and the upper bound is obtained with the Lokhov-Tkachov belt construction method. In contrast, the Bayesian approach facilitates the combination of results from individual measurement campaigns and the adoption of prior information from the other observations and model predictions. We will also discuss the Bayesian sensitivity for the first five measurement campaigns, as well as its prior dependency.
The Deep Underground Neutrino Experiment (DUNE) is a long baseline neutrino experiment for neutrino science and Beyond the Standard Model physics. The experiment will use in the first phase two far detector (FD) modules, 1300 km away from the beamline, installed 1.5 km deep underground. The FD modules will consist of Liquid Argon Time Projection Chambers (LArTPCs) with 17 kt of liquid argon each. Studying atmospheric neutrinos with LArTPCs offers a unique opportunity to probe the neutrino properties with exceptional precision over a wide energy range. In this work, I will present the energy and angle reconstruction algorithms developed for reconstructing atmospheric neutrino interactions. I will present the algorithmic performance evaluation of different reconstruction methods, using simulation data for a small-scale FD detector. Possible ways to improve the present algorithms to enhance DUNE’s sensitivity will also be presented.
In Super-Kamiokande, a 50-kton water Cherenkov detector, gadolinium (Gd) was loaded at concentrations of 0.01% in 2020 and of 0.03% in 2022, and a new observation phase called SK-Gd was started. The detection efficiency of neutrons is greatly improved to 50% with 0.01%Gd and to 65% with 0.03%Gd because gadolinium has a large cross section for neutron capture and produces high-energy gamma rays.
In this poster, we will report how the physics sensitivity of atmospheric neutrino oscillation analysis improves with this improved neutron detection capability. Atmospheric neutrino oscillations are good probes of the mass hierarchy and also sensitive to $\Delta m^2_{23}$, $\theta_{23}$, and $\delta_{CP}$, and the gadolinium is expected to improve their sensitivity in two main ways.
First, neutron tagging improves neutrino-antineutrino separation and thereby increases sensitivity to the mass hierarchy. Second, it allows improved kinematic reconstruction of the neutrino by accounting for more information carried by the hadronic system.
We report on the improvement of the sensitivity of the oscillation analysis, considering the uncertainty of the reconstruction.
To achieve a sensitivity of 40 meV/c$^2$ in neutrino mass measurement, the Project 8 experiment relies on cyclotron radiation emission spectroscopy of beta decay electrons from an atomic tritium source. Due to the radioactive nature of tritium, initial R&D work for source and diagnostic tools development is carried out with a hydrogen beam. Presently, a thermally heated hydrogen atom source, capable of reaching temperatures up to 2400 K, is employed at JGU Mainz. Molecular hydrogen passes through a 1 mm tungsten capillary, generating atoms through surface contact catalyzing due to tungsten’s dissociative adsorption isotherm for hydrogen. Various techniques are utilized to characterize the dissociation efficiency of this source. One such technique, able to measure the atomic dissociation fraction as well as the beam shape, is the wire detector.
Aging of the heating element, thermal shields, and capillary in the atom source will alter its surface structure over time, affecting the capillary’s resistivity and surface emissivity. To accurately assess the capillary’s temperature stability and establish the correlation between atomic fraction and temperature, a near-infrared (NIR) spectrometer and a visible range multi-channel camera are employed to measure the capillary's absolute temperature.
Results from measurements conducted at different flows (up to 20 sccm) and at various atom source temperatures will be presented for the wire detector, NIR spectrometer and camera. The source and beam results are crucial for optimizing the performance of the atomic tritium beam setup and advancing the goals of the Project 8 experiment.
The DUNE experiment will have a rich set of physics topics, including neutrino oscillation and Beyond Standard Model (BSM) physics. Of great importance to the latter of these goals in baryon number violation (BNV), especially including proton decay (PDK), neutron-antineutron transformations, and dinucleon decay. All suffer from atmospheric neutrino backgrounds, which at times mimic these rare events' unique topologies. In this poster, we will review recent results in this vein using the DUNE Far Detector, and look forward to some upcoming analyses.
We present three different projects on searches for searches of Heavy Neutral Leptons (also known in the literature as sterile neutrinos, right-handed neutrinos, or simply HNLs) in two different models.
The first project analyzes the sensitivity for parameters in the left-right symmetric model in the form of displaced HNLs in different proposals for lepton colliders: FCC-ee, CEPC, ILC, CLIC, and a muon collider.
Then, in the context of the minimal type-I seesaw, we improve the bounds on HNL parameters from searches in charged lepton flavor violating (cLFV) processes when we consider non-decoupling diagrams, which has been neglected in recent literature.
And finally, we present the bounds on Yukawa couplings of the minimal type-I seesaw that are allowed by tree level unitarity.
The Jiangmen Underground Neutrino Observatory (JUNO) will be a 20-kiloton liquid scintillator detector, currently under construction in southern China. Equipped with 17,612 20-inch photomultiplier tubes (PMTs) and 25,600 3-inch PMTs, JUNO aims to use its world-leading size, energy resolution and low background levels to achieve its primary physics goal of resolving the fine structure due to oscillations in the nuclear reactor antineutrino energy spectrum, in order to determine the neutrino mass ordering and measure several oscillation parameters to a sub-percent precision. As JUNO enters its commissioning and early data-taking periods, having steady, robust calibration methods that evolve with time will be of particular use. Here, the measurement of key liquid scintillator parameters is presented using Bi-Po coincidence decays, which naturally occur in MeV-scale liquid scintillator detectors.
The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose
neutrino experiment currently under construction in Jiangmen, southwest China.
Its main detector consists of a acrylic sphere of 35.4m in diameter, filled with
20kt of liquid scintillator. JUNO features a broad physics program, with the
determination of the neutrino mass ordering as the primary goal. However, this
goal can only be reached if a thorough background control of the experiment is
carried out. Especially, the use of radiopure materials is of upmost importance
to reduce neutrino-signal mimicking bismuth-polonium decays.
For the purpose of monitoring radiopurity of liquid scintillator (LS) batches
during the months-long filling of JUNO, the Online Scintillator Internal Radioactivity
Investigation System (OSIRIS) was developed. OSIRIS features a
central, watershielded 3m x 3m acrylic vessel (AV) filled with 18 tons of LS. The
AV is instrumented with an array of 76 Large Photomultiplier Tubes (LPMTs).
For the calibration of OSIRIS, two independent and partially redundant systems
are employed:A picosecond Laser Calibration System utilising sub-ns single photon
pulses is used for precise calibrations of LPMT timing and charge responses
in the spe regime. An Automated Calibration Unit (ACU) from the Daya Bay
experiment is employed for the calibration of energy and vertex reconstructions
via radioactive sources. The ACU is also hosts an LED, used for redundant
calibrations of LPMT timing and charge responses.
This poster will describe the calibration systems of OSIRIS, the expected performance
of the two systems, simulated performance of the calibration and very
first results from the commissioning of the OSIRIS detector.
JUNO is an experiment located in southern China that aims to determine neutrino mass ordering and perform precise measurements of neutrino oscillation parameters using reactor neutrinos. The calibration of the JUNO detector is a key step towards achieving these physics goals. In this poster, the calibration system will be introduced, followed by the calibration strategy of JUNO, including the calibrations of the PMTs, detector non-uniformity, and liquid scintillator non-linearity, among others. This poster will also cover how calibration data are used for the event reconstructions, going from the waveforms to the event energy.
Coherent elastic neutrino nucleus scattering (CEvNS) occurs when a neutrino interacts with the nucleus as a whole resulting in a recoil of the nucleus. The interaction requires neutrino energies below 50 MeV as prevalent at the pulsed beam of the Spallation Neutron Source at Oak Ridge National Laboratory. The COHERENT experiment is located there, detecting CEvNS with a multitude of different detector technologies.
The most recent detection was achieved with low threshold high-purity Germanium spectrometers during the summer beam run of 2023. We measured CEvNS on Germanium for the first time with an analysis threshold of 1.5 keV ionization energy and with more than 3 sigma significance.
On my poster, I will illustrate the analysis in detail and show how the detection was achieved. I will also provide a brief outlook on the future developments for the experiment.
In this study, we conducted a comprehensive characterization and optimization of a cryogenic pure CsI (pCsI) detector. Achieving a notable light yield of 35.2PE/keVee and a world-leading energy resolution of 6.9% at 60keV, we utilized a 2cm cubic crystal coupled with a HAMAMATSU R11065 photomultiplier tube (PMT). Additionally, we measured the scintillation decay time of pCsI, which proved to be significantly faster than that of CsI(Na) at room temperature. Furthermore, we investigated the impact of temperature, surface treatment, and crystal shape on the light yield. Notably, the light yield peaked at approximately 20K and remained stable within the range of 70-100K. We observed that the light yield of polished crystals was approximately 1.5 times greater than that of ground crystals, while the crystal shape exhibited minimal influence on the light yield. These results are crucial for the design of the 10kg pCsI detector for the future CLOVERS (Coherent eLastic neutrinO(V)-nucleus scattERing at China Spallation Neutron Source (CSNS)) experiment.
Recent results from neutrino experiments such as MINERvA, T2K, and NOvA have revealed notable disparities between simulated predictions and observed data in neutrino-matter interactions. These inconsistencies underscore the inadequacies of the leading theoretical models coded in the simulations, hence shadowing the full complexity of the interactions. A comprehensive understanding of the theoretical frameworks is imperative to address the disparities and to develop effective models that better represent neutrino-matter interactions. We focus on elucidating the challenges inherent in the identification of charged pions in the NOvA detectors, a crucial aspect of neutrino-matter interactions. By analyzing discrepancies and difficulties encountered in the reconstruction and identification stages in NOvA’s charged pion characterization, we aim to shed light on potential shortcomings in current simulation methodologies. In addition, we present a comparison between two types of Deep Learning techniques for their performance on charged pion identification in NOvA. One was developed outside the collaboration and the other is a custom algorithm for instance segmentation. This analysis main objective is to highlight the discrepancies between data and Monte Carlo samples in areas such as the multiplicity and the energy of the charged pions. Moreover, the analysis is developing strategies to identify and address failure modes in simulation algorithms and in further data analysis.
The RICOCHET experiment measures the spectrum of coherent elastic neutrino-nuclear scattering (CEνNS) of reactor neutrinos to search for physics beyond the Standard Model. In RICOCHET’s Q-Array detector, recoil energy deposited in an array of superconducting crystals is transferred to transition-edge sensors (TES) that convert temperature changes into current signals, which then get amplified and read out through a microwave multiplexer. Compared to more traditional multiplexing techniques such as time and code division multiplexing, a frequency-division multiplexer made with high Q superconducting resonators allows for faster pulse response, higher multiplexing factor, and lower power dissipation.
Together with Lincoln Laboratory, we designed, fabricated, and characterized aluminum microwave multiplexers in 6 and 18 channels configurations. The TES current signals couple inductively into RF SQUIDs that modulate the resonant frequency of the superconducting resonators, which all connect to a common RF feedline for signal readout. In this poster, we present some characterization results of this device, including sensitivity measurements, circuit parameter extraction, and the power dependence of the device behavior.
The NuMI Off-Axis $\nu_e$ Appearance experiment (NOvA) is designed to study neutrinos and their interaction properties with matter. NOvA is a long-baseline neutrino oscillation experiment consisting of the Near Detector at Fermi National Accelerator and Far Detector in Ash River, Minnesota aiming to determine the neutrino mass hierarchy, and constrain the charge-parity violation phase. In addition to oscillation measurements, the NOvA Near Detector samples are ideal for measuring neutrino-neucleus interaction cross sections, which are important for constraining uncertainties in oscillation analyses.
Here, we present the status of an analysis that will use data from the NuMI beam peaked at 1.8GeV of neutrino energy to measure the cross-section of $\nu_\mu+N\rightarrow\mu+N\pi+X$ as a function of muon and leading-pion kinematics, where $N\pi$ is any number of charged pions, and X represents any particles in the final state.
Neutrino telescopes see events of various morphologies: these are the shapes of the aggregate photon hits recorded by the optical module array, including electron neutrino-induced cascades, muon neutrino-induced tracks, and many more. Among these event morphologies, the double cascade ("double-bang") is a class of particular interest because it might indicate the detection of a tau neutrino. However, there are more exotic processes that might lead to a double-bang-like signature, among which is the production and subsequent decay of charmed hadron. In this study, we simulate neutrino-nucleus Deep Inelastic Scattering-induced charmed hadron production, its decay, and the corresponding detector response. We analyze the morphology of such a class of events in a comparison with tau neutrino-induced double-bang signatures, focusing on our ability to reconstruct and differentiate the two processes.
Separating Cherenkov from Scintillation light precisely and efficiently would allow a broad range of physics, especially in the neutrino field. The classification of Cherenkov and Scintillation photons in neutrino interactions is essential for better energy reconstruction, particle identification, and background separation. This classification can be carried out using traditional methods, and the implementation with techniques such as machine learning is also of great significance. Considering this importance, we’ve been trying several machine learning models and comparing results with the classical methods such as simple kinematic cuts. There are several parameters depending on the detector setup, geometry, etc. but in the scope of our study we focus on two main parameters; the arrival time and the energy of photons produced by neutrino interactions. In this study, we have tried several models including XGBoost, LightGBM, and RandomForest which currently give the top three best accuracies. We have been also doing hyperparameter tuning with these models, especially with XGBoost, in order to find the most optimized parameter list. Here, we present selected parameters, model results, and their comparisons between each model as well as the classical methods.
The CLOUD collaboration is pioneering the first fundamental research reactor antineutrino experiment using the novel LiquidO technology for event-wise antimatter tagging. CLOUD’s program is the byproduct of the AntiMatter-OTech EIC/UKRI-funded project focusing on industrial reactor innovation. The experimental setup consists of an up to 10 tonne detector, filled with an opaque scintillator and crossed by a dense grid of wavelength-shifting fibres. The detector will be located at EDF-Chooz’s new “ultra-near” site, ~35 m from the core of one of the most powerful European nuclear plants, with minimal overburden. In this poster we will introduce the scientific goals of the experiment divided into three main phases. CLOUD-I aims for the highest precision of the absolute reactor antineutrino flux, along with explorations beyond the Standard Model, detecting of order 10,000 antineutrinos daily and with a high (≥100) signal-to-background discrimination. CLOUD-II and CLOUD-III will exploit several metal-doped opaque scintillators to showcase further detection capabilities, including the first attempt at surface detection of solar neutrinos and the experimental feasibility of a novel approach for potassium geoneutrino detection, respectively.
Borexino, located at the underground Laboratori Nazionali del Gran Sasso in Italy, was a large liquid scintillator detector designed for real-time detection of low-energy solar neutrinos. During more than ten years of data taking, it has measured all the neutrino fluxes produced in the proton-proton chain, the primary fusion process responsible for 99 % of solar energy, as well as from the sub-dominant Carbon-Nitrogen-Oxygen (CNO) fusion cycle.
The determination of the CNO signal is performed through a multivariate spectral analysis, leveraging the excellent radiopurity achieved in Borexino. The main challenge of this measurement lies in independently determining the $^{210}$Bi contamination, essential for constraining its rate in the multivariate fit to break the anti-correlation with CNO neutrinos.
Recently, Borexino has introduced an innovative technique, called "Correlated and Integrated Directionality" (CID), based on the features of fast directional Cherenkov light. This method exploits the correlation between the known position of the Sun and the direction of reconstructed photons. Specifically, Cherenkov PMT hits generated by solar neutrino interactions correlate with the position of the Sun, while both isotropic scintillation light and hits produced by background events do not. Borexino has provided the proof of principle of this new method through the first directional measurement of sub-MeV $^7$Be neutrinos.
This poster presents the first observation of CNO solar neutrinos utilizing the CID technique. Unlike the spectral analysis, this measurement is performed without any prior information regarding the $^{210}$Bi contamination employing all Borexino available data. Furthermore, this result is combined with an improved two-dimensional multivariate analysis of the Phase III dataset, leading to the
final and most precise Borexino CNO measurement.
Pre-supernova (preSN) neutrinos are emitted by massive stars in the hours leading up to their core collapse. The detection of preSN neutrinos may provide insight into the evolution of massive stars and the processes culminating in their core collapse, as well as address open questions about neutrinos such as the mass hierarchy. Additionally it may provide early warnings for nearby supernovae, which is why the Kamioka Liquid Scintillator Antineutrino Detector (KamLAND) and the Super-Kamiokande (SuperK) have launched pre-supernova alarms in 2015 and 2021, respectively. SuperK and KamLAND have recently developed a combined alert system in order to improve their sensitivities to preSN neutrinos and to extend the expected warning times. We present the details of the combined alarm along with the expected increase in sensitivity.
Atmospheric neutrinos and cosmic-ray muons are generated from the showers of secondary particles via the interactions of primary cosmic-ray particles with air nuclei at the top of the atmosphere. The meson, such as pion and kaon, decays into atmospheric neutrino and cosmic-ray muon, reflecting the information of the hadronic interactions depending on their energy. Currently, atmospheric neutrino flux models have uncertainties about various points, such as neutrino/antineutrino ratio and absolute flux, and so on. To constrain these uncertainties, we consider the usable of cosmic-ray muon data. In this poster presentation, we report the measurement of the charge ratio of the cosmic-ray muons and the modulation of the arrival cosmic-ray muons at underground by analyzing the data accumulated by Super-Kamiokande detector. In addition, we consider about the constraint on the neutrino/antineutrino ratio from the result of the muon charge ratio, and on the parent meson ratio from the result of the muon modulation.
The Fluorescence Detector (FD) of the Pierre Auger Observatory has a large exposure for the detection of ultra-high-energy (UHE) upward-going showers (UGS) like the ones reported by ANITA.
Recently, strong limits on UGS were obtained using 14 years of FD data, which are in tension with the observations made by ANITA-I and III.
Furthermore, ANITA-IV has reported new UGS candidates.
Both of these observations motivate the exploration of Beyond Standard Model (BSM) scenarios.
In this work, we explore the parameter space to test three classes of BSM models.
These unknown BSM particles can interact inside the Earth and produce $\nu_\tau$, $\tau$, and $\tau$-like particles, which can further interact or decay.
Subsequently, some of the final products may escape the Earth and induce a UGS in the atmosphere.
Due to the non-observation of the UGS by the FD, the upper flux limits of these UHE BSM particles are obtained as a function of their possible cross-sections with matter.
In addition, stronger constraints are achieved by combining the Surface Detector and FD data of the Pierre Auger Observatory.
Identifying low energy activity in LArTPCs presents two main challenges: (1) the local topology is quite complex and highly variable, (2) interesting physics consists of several spatially separated blips which must be collected together. The first challenge makes separating different blip signatures which have similar underlying physics extremely difficult, since the distribution of their event topologies will often be indistinguishable. The second challenge refers to the fact that some low energy activity of interest, such as neutron captures, will necessarily consist of several blip topologies that are spread out in the detector, which must be exclusively associated to each other. To address these two challenges we introduce BlipNet, which consists of two main parts tailored to each of the challenges.
To combat the first challenge, we introduce a contrastive learning technique called BlipGraph which simply put, learns to separate the complex topologies of different low energy physics signatures by utilizing the various physical symmetries present in the data. Low energy activity is represented by point clouds which BlipGraph learns to separate by embedding them in a high-dimensional representation that respects rotational, translational and other symmetries. For the second challenge, we complement BlipGraph by constructing a topological representation of a LArTPC event called a decorated merge tree.
We present results for training BlipGraph and BlipNet on a simulated dataset for the ProtoDUNE single phase detector equipped with the pulsed neutron source. The BlipGraph model is optimized according to the linear evaluation protocol.
One of the primary goals of future galaxy and cosmic shear surveys such as the Euclid mission is to study dark energy and modified gravity models beyond LambdaCDM, shedding light on the nature of the late acceleration of the Universe. These observations will also be crucial to measure the absolute neutrino mass scale and constrain the effective number of neutrino species.
Cosmological constraints on the sum of neutrino masses are model-dependent and usually much tighter for LambdaCDM than in its extensions.
With currently available cosmological datasets, we study these constraints and degeneracies between the neutrino sector and cosmological parameters in beyond LambdaCDM models. Furthermore, we provide a glimpse of the future capabilities of the Euclid survey in the measurement of neutrino properties and the impact of the cross-correlation between the Euclid main probes with the cosmic microwave background, in inferring neutrino masses in modified gravity models.
For the operation of precision neutrino experiments, the understanding of neutrino interactions with matter are preconditioned requirements of all detections and measurements of neutrinos. The largest uncertainties in estimating neutrino-nucleus interaction cross sections arise in the incomplete understanding of nuclear effects. In the study of neutrino oscillations and nuclear scattering processes, obtaining an interaction model with associated uncertainties is of sub- stantial interest for the neutrino physics community. This report presents studies of simulated CC 2p-2h interactions, in which a neutrino interacts with a bound pair of nucleons. This interaction mode is very poorly constrained by current data. A comparison of three leading CC 2p-2h models is presented, along with a number of uncertainty parameters that have been implemented to account for model-to-model discrepancies in the DUNE oscillation analysis.
Cryo-PoF project is an R&D funded by the Italian Institute for Nuclear Research (INFN) in Milano-Bicocca (Italy) and it is based on Power Over Fiber (PoF) technology.
PoF technology delivers electrical power by sending laser light through an optical fiber to a photovoltaic power converter, in order to power sensors or electrical devices.
Cryo-PoF is inspired by the needs of the DUNE Vertical Drift detector, where the VUV light of liquid argon must be collected at the cathode, i.e. on a surface whose voltage exceeds 300 kV. To power both the Photon Detection devices and its electronic amplifier, we aim to develop a cryogenic system, solely based on optoelectronic devices and a single laser input line. The SiPM bias is given and regulated by the DC/DC converter developed by Milano Statale group. The DC/DC will include a remote control able to determinate different output voltages while operating on an external signal through an optical fiber connection at room temperature.
In this contribution are presented the results obtained during test campaign performed in Milano- Bicocca, with the emphasis on the development of the advanced DC/DC converter.
Evidence for the existence of dark matter strongly motivates the efforts to study its unknown properties. Additionally, the origin of high-energy astrophysical neutrinos detected by IceCube remains uncertain. Scotogenic models, in which neutrino mass generation occurs through interactions with the dark sector, are some of the leading theories that explain these two mysteries simultaneously. If dark matter and neutrinos couple to each other, we can search for a non-zero elastic scattering cross section. The interaction between an isotropic extragalactic neutrino flux and dark matter would be concentrated in the Galactic Center, where the dark matter column density is largest. The flux of high-energy neutrinos would be attenuated by this scattering, and the resulting signal, with correlated energy and arrival direction, can be observed in IceCube. Using the ten years of IceCube data, we perform a binned likelihood analysis, searching for several potential DM-neutrino interaction scenarios.
The Coherent CAPTAIN-Mills (CCM) experiment is a 10 ton liquid argon scintillation and Cherenkov detector at the Los Alamos Neutron Science Center. The detector is located 23m downstream from the Lujan Facility's stopped pion source which will receive 2.25 10^22 POT in the ongoing 3 year run cycle. The short duration 290ns proton pulse and delayed arrival time of spallation neutrons allows CCM to probe rare processes with very low backgrounds. The high-rate of pion production and intense flux of other particles at the Lujan source allow CCM to probe a wide variety of dark sector models, including possible explanations to the short-baseline neutrino anomalies and MeV-scale Axion-Like-Particles. We present the latest results from CCM as well as projections for its full 3yr run cycle.
The Short Baseline Near Detector is a liquid argon time projection chamber (LArTPC) composed of a variety of subsystems which each help collect different data elements. The TPC itself uses a wire-based readout to collect drifted ionization electrons. In conjunction with this charge readout system, there is also a photon detection system (PDS) composed of two methods of scintillation light detection, traditional PMTs and SiPM-based X-ARAPUCAs. The experiment also uses a cosmic ray tagger (CRT) made of solid scintillator strips; a dedicated system which handles the management and issuing of trigger signals; and a timing system that coordinates all of these components. In order to facilitate steady physics quality data taking, the data acquisition system (DAQ) must be fully developed and vigorously tested. Integrating all subsystems to run simultaneously, with synchronized timing and sufficient data throughput is a key aspect of commissioning the detector.
We explore the de-excitation of highly excited $^{11}$B$^*$ by use of the TALYS and GEMINI++ codes, which can deal with the decay of a compound nucleus by a series of sequential binary decays. For a liquid scintillator detector, the residual nucleus $^{11}$B$^*$ can be produced by neutrino interactions with $^{12}$C or proton decays in $^{12}$C. We use both the TALYS and GEMINI++ codes to estimate the de-excitation branching ratios of $^{11}$B$^*$ for a given excitation energy spectrum. It is found that the TALYS calculation can partly account for the current experimental results. Note that the preliminary result from GEMINI++ can give a better agreement with the experimental data.
Building upon the LiquidO detection paradigm, the CLOUD detector represents a significant evolution in neutrino detection, offering rich capabilities in capturing both spatial and temporal information of low-energy particle interactions. With a 5-10 ton opaque scintillator inner detector volume, CLOUD is the byproduct of the EIC/UKRI funded AntiMatter-OTech project, whose main objective is to make a high-statistics, above-ground measurement of antineutrinos at the Chooz reactor ultra near detector site. Possible physics measurements of CLOUD include the weak mixing angle, solar neutrinos using Indium loading, and geoneutrinos.
This poster focuses on exploiting CLOUD data through development of event reconstruction techniques required for precise measurement and classification of MeV-scale neutrino interactions. Leveraging the intrinsically segmented design of the CLOUD detector, we aim to capitalize on both timing and spatial signals to reconstruct neutrino interaction kinematics quickly and accurately. We outline innovative approaches to event reconstruction, emphasizing Likelihood-free inference density estimation techniques for reconstructing neutrino interaction kinematics. Furthermore, advanced event classification techniques incorporating symmetry-exploiting neural networks (e.g., CNNs and GNNs), will play a pivotal role in background rejection, enhancing the precision of our measurements.
The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is a neutrino detector at the Booster Neutrino Beam (BNB) at Fermilab. It is a gadolinium-doped water Cherenkov detector designed for measuring the neutron multiplicity in neutrino-nucleus interactions, as well as measuring the charged-current cross section of muon neutrinos. In addition, ANNIE has a strong focus on testing new detector technologies, amongst which is Water-based Liquid Scintillators (WbLS). It is a novel detection medium that allows the simultaneous detection of scintillation and Cherenkov light. To test the detection capabilities of WbLS, a 366 L cylindrical vessel filled with WbLS was deployed in ANNIE. The successful observation of both scintillation and Cherenkov light in ANNIE corresponds to a proof-of-concept for the hybrid event detection concept. This allows for the future development of dedicated algorithm for vertex reconstruction and particle identification algorithms. Additionally, a number of dedicated analyses are planned in ANNIE, that will make use of both the Cherenkov and scintillation component. This poster presents an overview of the WbLS activity in ANNIE.
The Ka rlsruhe Tr itium N eutrino (KATRIN) experiment aims to determine the mass of the electron antineutrino by precise measurement of the energy spectrum of $\beta$-electrons from tritium decay using a MAC-E-Filter setup. After a total measurement time of 1000 days in 2025, a final sensitivity better than $0.3\,\mathrm{eV/c^2}$ (90 % C.L.) is expected.
At the moment, one sensitivity limiting factor is the spectrometer background which consists of electrons that are generated in the main spectrometer volume. Due to their small initial energy, the background electrons have a different angular distribution than the signal electrons at the point of detection.
A scintillating structure acting as an angular selective detector (scint-aTEF) has potential to discriminate between $\beta$- and background electrons. Along with illustrating the concept of the scint-aTEF, the poster will give an update on the current development status of the scint-aTEF and show its expected impact on background reduction and neutrino mass sensitivity according to simulations.
This work is supported by the Helmholtz Association and by the Ministry for Education and Research BMBF (grant numbers 05A23PMA, 05A23PX2, 05A23VK2, and 05A23WO6).
ATLAS, a collider detector, can measure the flux of high-energy supernova neutrinos, which originate in the circumstellar medium from days to months after the explosion. Simulating predicted fluxes, we find at most around 0.1–1 starting events and around 10–100 throughgoing events from a supernova 10 kpc away. Possible Galactic supernovae from Betelgeuse and Eta Carinae are considered as demonstrative examples. We conclude that even with limited statistics, ATLAS has the ability to discriminate among flavors and between neutrinos and antineutrinos, making it a unique supernova neutrino observatory.
The Quantum Technologies for Neutrino Mass (QTNM) is a UK-based neutrino mass measurement experiment which aims to leverage advances in quantum technology to develop a new experimental apparatus to determine the absolute neutrino mass.
Sensitivity to neutrino masses in the 10meV/c^2 regime is well motivated by neutrino oscillation measurements, but is out of reach of the current state-of-the-art technology. A forward looking experimental programme incorporating recent technological advances will help us to reach this ambitious goal.
QTNM will use Cyclotron Radiation Emission Spectroscopy (CRES) to measure the beta-decay spectrum of atomic tritium, and hence perform an absolute neutrino mass measurement. The first demonstrator apparatus (CRESDA) pulls together cutting edge technologies: atomic magnetometry, atomic source production and containment, high frequency signal collection and quantum-limited microwave amplifiers.
This poster will give an overview of QTNM, detailing the current status of the proposed detector technologies, forthcoming measurement plans and future experimental outlook.
Photomultiplier tube (PMT) arrays are widely used for neutrino and dark matter detectors, such as liquid xenon (LXe) time projection chambers. We proposed using a new 2” four-anode PMT R12699-406-M4 from Hamamatsu for the future LXe detectors. The effective 1” active area is about an order of magnitude finer than the previously widely used 3” PMTs and offers better position reconstruction, which is essential for signal selection and background suppression. When arranged to have the same coverage percentage as a 3” PMT array, the high-granularity array has a wider effective dynamic energy range from keV to MeV. We constructed a test array of 36 PMTs (144 channels) to test the performance of the high-granularity PMT array.
The Pacific Ocean Neutrino Experiment (P-ONE) is a cubic-kilometre scale neutrino telescope to be deployed deep in the northern Pacific Ocean off the coast of British Columbia, Canada. P-ONE aims to observe high-energy neutrinos to identify and gain insights into the physical mechanisms behind their sources across the universe. The detector will be composed of an array of kilometre tall mooring lines instrumented with P-ONE Optical Modules (P-OMs) which detect Cherenkov light from neutrino-induced secondary particles within the detector volume. To ensure accurate reconstruction of incident neutrinos, both the optical properties of seawater and position of each module within the detector must be known to high precision. The ocean is a dynamic environment where both of these parameters can vary over time and so to achieve this goal, P-ONE includes a variety of calibration systems for both localized and ranged real time detector calibration measurements. These include acoustic receivers and emitters for spatial trilateration and small fast light flashers integrated into each P-OM. Furthermore, some P-OM modules in the detector will be replaced with unique P-ONE CALibration (P-CAL) modules which contain a larger well calibrated nanosecond flasher along with some detection elements of the P-OM. This contribution highlights the development, simulations, and lab measurements of these P-ONE calibration systems.
It is particularly challenging to discern between these two effects since the Hamiltonian of neutrino oscillation is modified in a similar manner by both Lorentz invariance violation (LIV) and non-standard interaction (NSI) in neutrino propagation. Their sole distinction is that the earth matter effect does not impact LIV, while NSI depends on matter density. Therefore, the theories defining NSI and LIV are absolutely equal for a fixed baseline experiment where matter density is constant. However, depending on their statistics with regard to the present and future bounds of these parameters, one can discriminate between these two scenarios in the long-baseline neutrino experiments since the NSI and LIV parameters have different current and future bounds. In this study, we try to distinguish between LIV and NSI in the context of DUNE and P2SO since these two upcoming experiments are expected to have very high statistics and be sensitive to the most significant matter effect. Our findings demonstrate that it is feasible to achieve good discrimination between LIV and NSI when considering LIV in the data and NSI in theory. For the parameter $a_{\mu \mu}$, P2SO yields the best separation between LIV and NSI at 3$\sigma$ C.L. In this case, the value of the LIV parameter for which separation is possible lies within its future bound if one considers the value of the NSI parameter to be constrained by the present experiments. When it comes to discriminating of this kind, P2SO is more sensitive than DUNE.
The spatial width of neutrino wave packets produced by radioactive sources is a debated topic. It has been shown that a sufficiently small neutrino width would have detectable effects for Standard Model neutrinos in JUNO and improve eV-scale sterile neutrino model fits to current data. Predictions for the neutrino width from radioactive sources vary by several orders of magnitude, depending on the underlying assumptions about the scale of parent localization. The experimental limits extracted from reactor neutrino oscillation data are too broad to exclude any models. The BeEST experiment extracts properties of neutrinos via energy measurements of entangled 7Li recoil nuclei from the electron capture decay of 7Be implanted into superconducting sensors. The high resolution of the BeEST recoil spectrum and quantum uncertainty principles are used to set limits on the scale of parent localization and the spatial width of the electron-neutrino wave packets. Assuming the spatial widths are a similar order of magnitude for anti-electron-neutrinos produced in reactor sources, our extracted number from the BeEST experiment excludes the possibility of detecting decoherence effects due to wave packet separation.
Knowing the evolution of our Galaxy is a difficult task. The finiteness of the speed of light can help us on cosmological scales, but it is not helpful if we want to investigate shorter distances. Some information can be extrapolated by analyzing concentrations of radionuclides in layers of material inside the Crust, but this could give us hints just on the evolution of the Solar System and its neighborhood. Indeed, the studies on the presence of $^{60}$Fe inside the Oceanic Crust point out the presence of one or multiple nearby ($O(10\,\text{pc})$) and recent ($O(\text{Myr})$) Supernovae. To further investigate, we propose the use of long-aged minerals, called $\textit{paleo-detectors}$. Neutrinos and other astroparticles passing through paleo-detectors could generate nuclear recoils that lead to the formation of defects, defined as tracks, still visible inside the mineral. By counting the number of tracks and measuring their lengths, we obtain information on the flux of astroparticles that passed through the mineral. With this work, we analyze the discovery potential of paleo-detectors to the neutrinos emitted by past Supernovae and how they could be used to assess an evolution on the rate of nearby Supernovae.
The Jiangmen Underground Neutrino Observatory (JUNO) is a large-scale liquid scintillator detector under construction for neutrino detection. The detector will be situated in a laboratory ~700 meters underground. As its primary physics goals, neutrino mass ordering and precision oscillation parameter measurements require stringent systematic control of its measured reactor neutrino energy spectrum.Dual calorimetry, a pioneering technique in the JUNO experiment, ensures high-precision systematics control in detector calorimetry by integrating two distinct photosensor and electronic systems. This setup encircles a 20 kton liquid scintillator, featuring a photon-integration-based system with approximately 17,600 20-inch large PMTs (LPMTs) and a photon-counting-based system with around 25,600 3-inch small PMTs (SPMTs). The LPMT system is designed for maximal light detection to achieve 3% energy resolution at 1MeV. As the second calorimetry, the SPMT system is introduced to disentangle the degeneracy of calorimetry responses, isolate the charge non-linearity effects and provide a linear charge reference for LPMT. This dual-system approach enhances LPMT charge measurement accuracy through meticulous reconstruction, calibration, and monitoring, thereby fortifying JUNO's systematic control and measurement accuracy. Central to this strategy is the Dual Calorimetry Calibration (DCC), designed to fine-tune each LPMT channel's potential non-linear charge responses using UV laser, radioactive, and cosmogenic sources. Due to their design, the SPMTs can serve as a robust linear charge reference for LPMTs, thus controlling their charge response. This poster delves into the dual calorimetry's scientific basis, detailing its motivation, conceptual framework, and the DCC's methodology and anticipated efficacy. The discussion extends to practical DCC application techniques utilizing UV laser and radioactive sources.
DUNE (Deep Underground Neutrino Experiment) is a long-baseline neutrino experiment that will precisely measure neutrino oscillation parameters, observe astrophysical neutrinos, and search for processes beyond the standard model (such as nucleon decays, heavy neutral leptons, and accelerator-produced dark matter). DUNE will build four Liquid Argon Time Projection Chamber detectors (LAr-TPC) with a total mass of ~70 kt LAr located at Sanford Underground Research Facility (SURF), 1.5 km below the earth’s surface. Among the different detection channels in LAr, the most dominant is the charged current (CC) absorption of νe on 40Ar, for which DUNE’s observable will be short electron tracks and deexcitation gammas from the resulting 40K* final state. Additionally, the elastic scattering (ES) channel produces an electron track that conserves directionality, which will allow DUNE to pinpoint the astrophysical origin of the detected neutrinos. Our sun produces a continuous flux of neutrinos as a byproduct of fusion reactions. The products of the two most energetic processes (8B and hep chains) will be accessible to DUNE with neutrino energies centered at 10 MeV at an expected interaction rate of ~10⁻³ Hz. DUNE’s solar analysis has the potential of characterizing for the first time the contribution of the hep chain to the solar neutrino spectrum as well as constraining the best-fit measurements of Δm²12 of previous solar and reactor experiments.
In the pursuit of precise neutrino event simulation, the ICARUS experiment within the Short-Baseline Neutrino (SBN) program at Fermilab uses an overlay technique to closely align simulations with experimental data. This technique consists of taking signals from data from each of the each of the three subsystems (TPC, PMT, CRT) and overlaying a simulated neutrino interaction onto the event. The overlay procedure includes superimposing simulated waveforms from neutrino interactions from both Time Projection Chambers (TPC) and Photomultiplier Tubes (PMTs) onto their respective data counterparts. Furthermore, the Cosmic Ray Tagger (CRT) hits from both data and simulations are combined to form the overlay event. By combining signals in this manner, we can obtain a data-driven modeling of cosmic backgrounds as well as the detector response enabling a more precise handling of noise sources when using neutrino simulations.
TAMBO is a next-generation neutrino observatory to be deployed in the Colca Valley in the Peruvian Andes. The TAMBO detector array will be composed of small detectors deployed over several square kilometers on the slopes of the canyon. This area has significant touristic, agricultural, and cultural value for the local population. While these facilities promise both educational and economic development for their host communities, it is not uncommon for the establishment of such research sites to be met either with skepticism or intense local opposition. In previous instances, this opposition has originated both from scientists ignoring the concerns of host communities and from a lack of shared (scientific) understanding and interest from the host community. In this poster, we propose strategies for siting observatories and engaging with local communities, derived from comprehensive discussions with anthropologists, sociologists, policymakers, and scientists. These recommendations, while crucial for TAMBO's development, also hold universal relevance for large-scale neutrino detectors situated in rural settings, outlining how scientists can responsibly engage host communities when searching for a particular experimental site.
The CUPID experiment has embarked on a groundbreaking journey in the search for neutrinoless double beta decay (0$\nu\beta\beta$), leveraging innovative detector technologies to push the boundaries of sensitivity.
Preliminary measurements were conducted using the CUPID BDPT (CUPID
Bolometric Detector Prototype Tower), the inaugural prototype tower designed to evaluate the novel detector architecture. The primary aim was to assess the thermal scheme of the tower under low-temperature conditions. The test was successful in terms of stable and uniform thermalisation of all detectors along the tower, affirming
the reliability of the tower's design. Additionally, the performance of the Li$_2$MoO$_4$ (LMO) detectors integrated into the prototype tower was examined. These detectors displayed optimal energy resolution (~5 keV), and background rejection capabilities (DP$\alpha$ vs $\beta$/$\gamma$ > 3), when combined with the light detectors (LD) output.
The poster will provide a brief overview of the findings from the CUPID first tower prototype experiment, highlighting the successful validation of the tower's thermal scheme and the commendable performance of LMO detectors. These results are driving the current optimisation steps towards the completion of the final CUPID detector design.
Since the beginning of data taking, the Super-Kamiokande (SK) experiment has been conducting ground-breaking studies of solar neutrinos. All measurements to date, including those from SNO and KamLAND, are consistent with solar neutrino flavor change due to matter enhanced neutrino oscillations. But we are not yet done with solar neutrinos! Two key phenomena are yet to be observed with high significance: the energy dependence in the electron neutrino survival probability, driven by matter effects in the Sun (called the Mikheyev-Smirnov-Wolfenstein effect), and the day-night solar neutrino flux asymmetry, driven by matter effects in the Earth.
Super-Kamiokande measures $^{8}\text{B}$ and hep solar neutrinos via neutrino-electron elastic scattering. These are the highest energy solar neutrinos, but still quite close to SK’s lowest energy threshold of 3.5 MeV. As a result, the current systematic uncertainties of the detector’s energy scale limit the determination of the solar neutrino flux and energy spectrum with the required precision.
This poster describes the results from energy calibrations performed in three operational phases of SK, including both the pure water and gadolinium-loaded phases. The absolute energy scale of the detector is calibrated by injecting monoenergetic electrons into the tank using a linear accelerator (LINAC). However, these electrons can only be injected in the downward direction and data-taking positions are limited due to the arduous process of handling the LINAC device. To evaluate the systematic uncertainties of the energy scale, $^{16}\text{N}$ atoms produced by a deuterium-tritium (DT) generator are used. $^{16}\text{N}$ atoms decay isotropically, allowing us to measure the direction dependence of the energy scale. Furthermore, the DT device is easier to handle, making it suitable for taking data at many positions in the tank and evaluating the position dependence of the energy scale. These results are presented, along with a discussion of how the energy scale-related systematics can be further reduced to observe the long-sought-after solar neutrino matter effects.
In the study of reactor and geo antineutrinos, tagging of the inverse beta decay (IBD) positron-neutron coincidence signature allows for the elimination of most backgrounds. In many detectors, the primary remaining background is caused by $\alpha$ captures on 13C — so called ($\alpha$, n) events — which release a neutron and closely mimic the IBD's signature. The most common ($\alpha$, n) prompt event is produced by protons recoiling from the neutron, which gives rise to a distinct pulse shape compared to that of the positron from an IBD. A powerful classifier is thus presented, able to purify the IBD signal from most of its ($\alpha$, n) background, by discriminating between these pulse shapes. Particular attention is paid to the construction of appropriate training data from Monte-Carlo simulations. The tuning of the $\beta$ and proton scintillation timing models in these simulations for SNO+ is also discussed. Tuning of the former is achieved via the selection of a high purity sample of in-situ ${}^{214}$Bi to ${}^{214}$Po decays. The latter makes use of the deployment of a radioactive Americium-Beryllium source. Finally, results of this classification
We explore how neutrino quantum decoherence could affect the accuracy of standard neutrino oscillation parameter measurements in the DUNE and T2HK experiments. Our analysis reveals that the measurements of $\delta_\text{CP}$, $\sin^2\theta_{13}$, and $\sin^2\theta_{23}$ are more significantly impacted in DUNE compared to T2HK. Conversely, DUNE exhibits greater sensitivity to detecting decoherence effects than T2HK. Through a combined analysis of DUNE and T2HK data, we demonstrate the potential for achieving robust measurements of standard parameters, which may not be achievable with DUNE data alone.
The Jiangmen Underground Neutrino observatory (JUNO) will be a versatile 20 kton liquid scintillator detector with a large spectrum of physics objectives. It is currently under construction in China, with its filling set to start in 2024. The primary goal of JUNO is to determine the neutrino mass ordering by detecting the vacuum oscillation pattern of reactor antineutrinos over a baseline of 52.5 km. Thanks to its gigantic size and the 78% light coverage afforded by its dual calorimetric systems – including 17,612 20'' and 25,600 3'' photomultiplier tubes – JUNO will be able to capture atmospheric neutrinos at an expected rate of approximately 10 events per day. The MSW effect on the oscillation of atmospheric neutrinos induced while they traverse the Earth's matter can be explored to enhance the neutrino mass ordering measurement in JUNO, provided the energy, direction, and flavor of multi-GeV neutrinos can be reconstructed. This poster presentation showcases the analysis strategy and the status of some of its key ingredients.
Studying the conservation/violation of CP symmetry in the leptonic sector is very essential in understanding the evolution of the universe. Lorentz and CPT invariance are fundamental symmetries of nature. Breaching of Lorentz invariance can also lead to CPT violations. We can examine the signature of Lorentz invariance and CP violations within the standard three-flavor neutrino oscillation framework. The scope of this research is how CPT-violating Lorentz invariance violation (LIV) parameters $a_{e\mu}, a_{e\tau}, a_{\mu\tau}$ impact the sensitivity to CP violation. Specifically, our focus is directed towards evaluating sensitivity within two proposed setups for the forthcoming T2HK experiment: (i) individual detectors placed at 295 km and 1100 km [T2HKK], and (ii) a detector with double capacity positioned at 295 km [T2HK]. We explore the role of different beam channels and the synergy between them in the context of CP sensitivity.
The NuWro Monte Carlo generator has been improved by taking into account the results of theoretical calculations for MEC from the work of J.E. Sobczyk, J. Nieves, F. Sanchez [Phys.Rev.C 102 (2020) 024601]. MEC events lead to the ejection of two or three correlated nucleons. These correlations are simulated using latent parameters. Predictions after the FSI from NuWro are compared to experimental results for proton observables obtained by experimental collaborations T2K and MINERvA.
The PandaX-4T experiment operates a dual-phase liquid xenon time projection chamber that is located in China Jinping Underground Laboratory. Searches for novel electronic recoil signals (NERS) in such type of detector due to solar axions, axion-like particles, dark photons, and neutrinos with an enhanced magnetic moment have attracted increasing attention as they could provide evidence for physics beyond the Standard Model and the Majorana nature of neutrinos. This poster will present the search results for NERS using both run-0 and run-1 low-energy electronic recoil data of PandaX-4T with a total exposure of 1.63 ton*year.
In the realm of physics beyond the Standard Model, Non-Standard Interactions (NSI) in neutrinos have emerged as a significant area of interest. While NSIs of neutrinos are mediated by a vector field ($Z^\prime$), recent research has delved into a novel form of neutrino interaction with matter mediated by light scalar particles, known as Scalar NSI (SNSI). SNSI appears as a Yukawa coupling term, altering the neutrino mass matrix and consequently affecting neutrino oscillations. It emerges as an additional matrix, giving rise to three real diagonals ($\eta_{\alpha \alpha}$) and three complex off-diagonals ($\eta_{\alpha \beta}$) SNSI parameters, which are dimensionless in nature. Our motivation for this work is to put bounds on these SNSI parameters, especially off-diagonal parameters ($\eta_{e\mu}, \eta_{e\tau}$ and $\eta_{\mu\tau}$). These are associated with new CP phases ($\phi_{\alpha\beta}$) that can have an additional impact on the sensitivity to determine the unknowns of the neutrino sector. We have shown the impact of SNSI parameters in the context of two future-based long baseline experiments, DUNE and P2SO and obtained more constrained sensitivity limits on $\eta_{e\mu}$ and $\eta_{e\tau}$ compared to $\eta_{\mu\tau}$ at 3$\sigma$ C.L. Additionally, we have studied the non-trivial behaviour of the oscillation parameter $\Delta m^2_{31}$ in the presence of SNSI parameters for P2SO and DUNE experiments.
We have observed that SNSI parameters significantly affect the CPV sensitivity of the long-baseline experiments. Interestingly, certain values of the SNSI parameters can vanish the CP sensitivity of both experiments.
Inorganic crystal scintillators, especially doped alkali-halide scintillators such as NaI[Tl], CsI[Tl] and CsI[Na], play an important role in neutrino experiments. The pioneering achievement of the COHERENT experiment, utilizing CsI[Na] for the initial detection of Coherent Elastic Neutrino-Nucleus Scattering (CEvNS), demonstrated a nuclear recoil detection threshold of approximately 8 keV(nr). However, to advance the capabilities of next-generation neutrino detectors, it is crucial to significantly reduce this detection threshold. Recent studies have illustrated that undoped alkali-halide scintillators, when operated at cryogenic temperatures near 77 K, exhibit a substantial increase in light yield – nearly doubling that of their room-temperature counterparts, alongside diminished afterglow effects. This poster outlines the advantages of adopting undoped, cryogenic CsI as a novel detector material for CEvNS experiments, focusing on its implementation in the COHERENT experiment at the SNS, offering a promising pathway to unlocking new physics through enhanced neutrino detection sensitivity.
Experimental discoveries in recent decades have provided valuable information on the nature of neutrino masses and mixings and present the first evidence for physics beyond the standard model. Moreover, massive neutrinos are now serving as an ideal tool to help unlock the mysteries of the matter abundance in the Universe.
At the same time the questions related to nature of neutrino masses, detection of relic neutrinos, and existence and role of sterile neutrinos are not answered.
We are looking at concepts to utilize low-energy neutrinos in the keV energy range and below. Examples include a production of monochromatic (anti)neutrinos in the bound-beta decay process and its detection via the resonant capture. One of the initial priorities would be observing anti-neutrino resonance. Such program could enable various measurements. Once the demonstration experiments are designed and concluded, assuming success, the community could start developing techniques that would assist with the detection of the lowest energy neutrinos. These concepts will be discussed in the presentation.
In this poster we describe in detail the feasibility of detecting $^{8}$B solar neutrino at JUNO with three reaction channels (neutrino-electron elastic scattering, neutrino-13C charged current, and neutral current interactions). A reduced 2 MeV threshold on the recoil electron energy is achievable with optimized background reduction strategies. The advantage of JUNO for charge and neutral current channel detection is a large amount of $^{13}$C (~0.2 kt). With ten years of data taking, about 60,000 ES signals and 600 NC/CC signal are expected. This leads to a simultaneous measurement of sin$^{2}\theta_{12}$ and ∆m$_{21}^{2}$ using reactor antineutrinos and solar neutrinos in the JUNO detector.
JUNO (Jiangmen Underground Neutrino Observatory) is a multipurpose neutrino physics experiment currently under construction in China. Its central detector consists of an acrylic sphere, filled with 20 kton of organic liquid scintillator, and a stainless steel structure, built to sustain 43212 photomultiplier tubes (PMTs) around the sphere. Thanks to its unique features, such as its huge active mass, a great PMT geometrical coverage and a complex strategy for the radioactivity control of all its components, JUNO is a perfect candidate to study solar neutrinos. Solar neutrinos mainly interact through elastic scattering reactions with liquid scintillator electrons. Hence, due to the absence of multiple events in temporal coincidence, all the decays of unstable nuclei will be backgrounds.
Two different techniques can be adopted to statistically separate solar neutrino events from background ones: the spectral analysis, which exploits the different energy spectral shapes of signals and backgrounds; and the Correlated and Integrated Directionality (CID) analysis, recently developed by the Borexino collaboration. CID relies on the directionality of the Cherenkov light: in solar neutrino events, the PMT hits caused by Cherenkov photons exhibit a correlation with the Sun’s position. The Cherenkov light is sub-dominant in JUNO (<1% of the total detected photons), however, thanks to its instant emission, the early PMT hits retain the directional information. Contrarily, for background events, no PMT hit shows any correlation with the Sun’s position.
Our preliminary studies show that the application of CID is feasible in JUNO. In this contribution, the CID technique will be introduced and its application for the measurement of 7Be and CNO neutrinos in JUNO will be presented. Finally, the strategy to combine the spectral and the CID analyses will be shown: the combination might improve JUNO’s sensitivity to 7Be and CNO solar neutrinos.
The PROSPECT experiment, known as the Precision Reactor Oscillation and SPECTrum, aims to examine the spectrum of antineutrinos emitted by the High Flux Isotope Reactor (HFIR) and investigate potential oscillations over short distances. The most recent publication by PROSPECT showcases an improved analysis, enhancing previous findings by incorporating a method called Single Ended Event Reconstruction (SEER) to utilize previously unused segments, as well as employing careful data splitting (DS) of different time periods to maximize the available data.
The utilization of SEER and DS has resulted in a significant increase in data quantity and a higher signal to background ratio, enabling PROSPECT to achieve one of the most accurate measurements of the antineutrino spectrum emitted from a purely $^{235}$U-fueled reactor.
%By comparing these measurements with the Huber-Mueller conversion model, a localized excess is observed within the energy range of 5 MeV to 7 MeV. These findings are consistent with observations made by other reactor experiments. The magnitude of the excess observed by PROSPECT, relative to that reported in commercial reactor experiments, provides new insights into the origin of the discrepancy between data and model.
In this poster we will delve into PROSPECT's updated dataset and discuss the unfolding technique used to map the reconstructed energy spectrum to the antineutrino energy. PROSPECT's antineutrino spectrum will be discussed and its implications to known discrepancies with current conversion models. Furthermore, we will highlight the most recent results of PROSPECT's reactor antineutrino flux and directionality studies.
This work was performed under the auspices of the US DOE Office of High Energy Physics by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-XXXXX.
With the CONUS reactor antineutrino experiment, the coherent elastic neutrino nucleus scattering (CEνNS) on germanium nuclei was studied at the nuclear power plant in Brokdorf, Germany. Very low energy thresholds of about 210 eV were achieved in four 1 kg point contact germanium detectors operated inside an optimized shield structure. The most recent results obtained during the final phase of data collection at the Brokdorf site are presented. The constraints on the CEνNS rate as compared to the previous CONUS analysis were improved by an order of magnitude and are now within a factor 2 of the signal rate predicted by the Standard Model.
Massive and deep underground detectors such as the future Deep Underground Neutrino Experiment (DUNE) will offer a great opportunity to search for rare, beyond-the-Standard-Model (BSM) physics signals including baryon number violating (BNV) processes. One such BNV process is nucleus-bound neutron-antineutron transition, followed by antineutron annihilation on a nearby neutron/proton that produces multiple final state pions, characterized by a unique, star-like topological signature. This signature should be easily recognizable within a fully active liquid argon time projection chamber (LArTPC) detector. While the future DUNE LArTPC can search for this signature with high sensitivity, existing data from the much-smaller MicroBooNE LArTPC can be used to demonstrate and validate the methodologies that can be used as part of the DUNE search. This poster presents a deep learning-based analysis of MicroBooNE data, making use of a sparse convolutional neural network (CNN) and event topology information to search for argon-bound neutron-antineutron transition-like signals in MicroBooNE. This analysis demonstrates LArTPCs’ capability, combined with deep-learning techniques, to search for such rare processes with high signal efficiency and strong background rejection.
The T2K experiment was commissioned with the primary task of measuring neutrino oscillation parameters. The near detector site has the purpose of measuring the neutrino beam composition close to the source, as well as constraining the main sources of systematic uncertainty on the oscillation fits such as the interaction cross section. The near detectors are capable of measuring neutrino-nucleus cross sections with remarkable precision on a variety of targets. This poster will present new results for electron neutrino charged-current pion production cross section measured using the off-axis near detector, ND280. The cross section results presented also represent the world's first measurement of this process on a carbon target. Although a subdominant interaction, this channel is of importance at T2K, as the far detector sample which measures this process shows a statistically significant event excess. This process will also continue to be of relevance at future long-baseline neutrino experiments.
The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is a 26-ton water Cherenkov detector that operates in the path of the Booster Neutrino Beam at Fermilab. ANNIE’s studies of neutrino-nucleus interactions in water-based targets have the potential to reduce systematic uncertainties in future long-baseline neutrino oscillation experiments. At the same time, ANNIE serves as an effective test platform for a range of advanced detector technology, including innovative water-based detection media and the novel photosensors known as Large Area Picosecond Photodetectors (LAPPDs).
We present preliminary event reconstruction of the first beam neutrinos ever detected with an LAPPD and evaluate the early performance of these photodetectors in the context of a neutrino experiment. We also consider lessons learned from the commissioning and deployment of the first integrated LAPPD system ever operated underwater as part of an active physics experiment.
The Ricochet experiment aims at measuring the coherent elastic neutrino-nucleus scattering (CEνNS) of reactor antineutrinos at the Institut Laue-Langevin, ILL (Grenoble, France). Ricochet employs two detector technologies to measure the CEνNS: (1) germanium cryogenic calorimeters with neutron-transmutation-doped thermistors (called Cryocube); (2) cryogenic calorimeters with a superconducting target and a transition-edge sensor readout (called Q-array). The Cryocube exploits a combined readout of phonons and ionization to identify nuclear recoil events and reject other backgrounds (electron recoils). The Q-array will use pulse shape discrimination related to the different timescales of quasiparticle recombination and phonon relaxation for electron- and nuclear-recoils respectively. The cryogenic facility was installed at the end of 2023 and validated at the nuclear reactor. The detector commissioning started in February 2024 with a detector payload of three 40-gram germanium detectors. The design of the facility, the discovery sensitivity and the first results of the commissioning phase of the Ricochet experiment will be presented in this contribution.
Neutrino telescopes present a novel opportunity to search for a coupling between Heavy Neutral Leptons (HNLs) and tau neutrinos via mass mixing. These searches can leverage the tau neutrino flux from the oscillations of atmospheric muon neutrinos as they traverse the Earth. This work presents the first search for HNLs using ten years of data from IceCube’s DeepCore sub-array. These results serve as a proof-of-concept for HNL searches in IceCube, enabled by the development of tailored HNL simulation tools. Progress on the development of a new reconstruction to enhance the identification of HNL events by capitalizing on their unique morphology will also be presented.
The Taishan Antineutrino Observatory (TAO) is a satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO) to precisely measure the reactor neutrino spectrum with sub-percent energy resolution at 1 MeV. The TAO detector is a 2.8-ton Gd-doped liquid scintillator (LS) detector and the LS is contained in a spherical acrylic vessel and viewed by $\sim 10\ \rm m^2$ inward-facing SiPMs corresponding to a coverage of 94%. We use an inhomogeneous Poisson process and Tweedie generalized linear model (GLM) to describe the SiPM response. We develop a pure probabilistic method using the time and charge of SiPMs from first principles to reconstruct point-like events in the TAO detector. After validation with the TAO simulation data, the performance of our model is found to be quite promising, showing a vertex position resolution better than 16 mm and an energy resolution of about 2% at 1 MeV. Our methodology is also applicable to other experiments that utilize PMTs for time and charge readouts.
Uncertainties in neutrino-nucleus cross-section measurements are usually evaluated by considering the spread of a measurement over an ensemble of variations of systematic parameters under the assumption they are distributed as a multivariate gaussian.
However, this cannot always be expected to be a safe assumption, in particular as we enter an era of systematic-limited measurements.
We showcase examples in which this assumption leads to incorrect conclusions when benchmarking neutrino interaction models and propose a solution to the issue.
We propose a method of directly learning the density of throws based on flow matching - a state-of-the-art generative modelling paradigm for training continuous normalizing flows.
We test our method in a realistic cross-section measurement example, showing it achieves excellent high-dimensional density estimation, surpassing the gaussian baseline and other machine learning methods.
The Jiangmen Underground Neutrino Observatory (JUNO), under construction in southern China, will determine the neutrino mass hierarchy (MH) by observing neutrinos from nuclear reactors at a distance of 53 km. To reach the desired sensitivity (> 3σ) for MH, the radiopurity of the detector materials and especially the liquid scintillator (LS) plays a crucial role. To ensure the purity of the 20 kt target of JUNO, the OSIRIS pre-detector (Online Scintillator Internal Radioactivity Investigation System) has been constructed and is currently under commissioning. It will monitor the radiopurity of the LS during its production and the filling phase of the central detector of JUNO.
This poster will focus on the design principles and hardware of the OSIRIS pre-detector. The 9-by-9m water-filled detector tank holds a well-shielded acrylic vessel filled with 20-ton of LS. is currently under commissioning. Equipped with 76 PMTs, it detects scintillation light from radioactive decays in the LS. The poster will cover a description of the entire DAQ chain that is closely modelled to the later situation in JUNO as well as the Liquid Handling System that will permit continuous exchange of the LS during the JUNO filling phase.
Super-Kamiokande (SK) has the powerful capability of independently determining the supernova (SN) pointing direction from the burst neutrinos. These produce a 3-d distribution of outgoing charged leptons around the neutrino flux direction in the water volume. A new, novel SN direction reconstruction method developed for SK uses HEALPix as a data structure for analyzing the reconstructed burst events to extract the SN direction. Burst events are mapped to pixels on the HEALPix sphere according to their directions. Gaussian smoothing is applied to the sparse event distribution to produce a smooth 3-d angular distribution without altering the pixel resolution. The resulting event-loaded HEALPix sphere has a peak in the direction of the neutrino flux from the electron elastic scatter (ES) events. The SN direction is then found from the ES peak centroid. The pixel size and smoothing parameters were optimized to maximize angular resolution and minimize failure rate for bursts at a range of distances. The HEALPix-based method has better angular resolution than the previous SK direction fitter and is significantly faster, with a computation time of a few seconds. This improves the ability of SK to provide an accurate SN pointing direction before the arrival of the shock breakout radiation. This poster describes the new method and the resulting performance.
The ENUBET project recently concluded the R&D for a site independent design of a monitored neutrino beam for high precision cross section measurements, in which the neutrino flux is inferred from the measurement of charged leptons in an instrumented decay tunnel. In this phase three fundamental results were obtained and will be discussed in this talk: 1) a beamline not requiring a horn and relying on static focusing elements allows to perform a $\nu_e$ cross section measurement in the DUNE energy range with 1% statistical uncertainty employing 10$^{20}$ 400 GeV protons on target (pot) and a moderate mass neutrino detector of the size of protoDUNE; 2) the instrumentation of the decay tunnel, based on a cost effective sampling calorimeter solution, has been tested with a large scale prototype achieving the performance required to identify positrons and muons from kaon decays with high signal-to-noise ratio; 3) the systematics budget on the neutrino flux is constrained at the 1% level by fitting the charged leptons observables measured in the decay tunnel.
Based on these successful results ENUBET is now pursuing a study for a site dependent implementation at CERN in the framework of Physics Beyond Colliders. In this context a new beamline, able to enrich the neutrino flux at the energy of HK and to reduce by more than a factor 2 the needed pot, has been designed and is being optimized. The civil engineering and radioprotection studies for the siting of ENUBET in the North Area towards the two protoDUNEs are also in the scope of this work, with the goal of proposing a neutrino cross section experiment in 2026. The combined use of both the neutrino detectors and of the improved beamline would allow to perform cross section measurements with unprecedented precision in about 5 years with a proton request (<0.5x10$^{18}$ pot/year) compatible with the needs of other users after CERN Long Shutdown 3. An update on the status of these studies and future plans will be presented.
The Short-Baseline Near Detector (SBND) at Fermilab is a Liquid Argon Time Projection Chamber (LArTPC) experiment designed to capture neutrinos from the Booster Neutrino Beam (BNB). Its proximity to the beam target (110 m) and large size (112 tons) enable the recording of millions of neutrino interactions annually. SBND provides the highest statistics worldwide for neutrino-argon cross-section measurements, facilitating the study of rare channels like Cabibbo-suppressed QE hyperon production. Specifically, this poster focuses on neutral Λ baryon production. Our work introduces a novel selection strategy leveraging LArTPC imaging capabilities to identify the distinctive decay signatures of Λ baryons, enhancing sensitivity to this channel.
We present an implementation of the npnh model of Martini et al in the GENIE neutrino nucleus interaction event generator along side subsequent comparisons of the model predictions to neutrino cross-section measurements. The Martini model includes a particularly comprehensive description of npnh interactions, considering MEC, SRC and interference contributions in addition to a contribution from 3p3h interactions. Its implementation in GENIE allows neutrino oscillation analyses to benchmark their input interaction models and motivates a more complete treatment of their systematic uncertainties.
Making high-precision measurements of neutrino oscillation parameters requires an unprecedented understanding of neutrino-nucleus scattering. To help fulfill this need, MicroBooNE has produced an extensive set of multi-differential charged-current muon neutrino cross-section measurements which probe the leptonic and hadronic systems. This poster presents the first energy dependent multi-differential cross-section measurement and simultaneous measurements of final states with and without protons for the inclusive channel. None of the predictions from commonly used neutrino event generators were able to adequately describe the entirety of this data, especially below 1 GeV of neutrino energy and when no protons are present in the final state. Furthermore, to more directly probe the nuclear effects which complicate the modeling of neutrino-argon interactions, we present the first charged current double-differential cross-sections in kinematic imbalance variables using events with no detected final-state pions. These variables characterize both the transverse and total kinematic imbalance in a neutrino interaction and are sensitive to the modeling of final-state interactions, Fermi motion, and multi-nucleon processes.
Since their first detection, neutrinos have offered several experimental anomalies, each leading to significant discoveries and broadening our understanding of fundamental interactions. Several such anomalies, however, remain unresolved. Those include the LSND, MiniBooNE, and Gallium anomalies, each of which can independently be interpreted as neutrino oscillations involving the addition of (at least) a fourth neutrino type with mass in the 0.1-10 eV range. The Short Baseline Neutrino Program at Fermi National Laboratory has finally been realized, employing a suite of liquid argon time projection chamber detectors at different baselines, with the operation of its final, near detector beginning in 2024. The primary goal of this program is to definitively address the aforementioned short baseline anomalies. Combined, the Short Baseline Near Detector (SBND) and its far detector counterpart, ICARUS, offer unprecedented sensitivity reach to light sterile neutrino oscillations, leveraging advances in liquid-argon time projection chamber technology and the largest neutrino dataset ever, to be collected. To reach that goal, advanced event selections need to be developed, as well as multi-detector, multi-channel high-performance fitting frameworks. This poster discusses the latest progress being made on these fronts and highlights remaining challenges.
Weakly Interacting Massive Particles (WIMPs) are the most suitable particle dark matter candidates. These can be gravitationally captured into massive celestial objects, such as the Sun, where they can accumulate and then self-annihilate into Standard Model particles, also yielding neutrinos. Neutrino telescopes, large arrays of photo-sensors, can search for this indirect signal of the presence of dark matter by searching for neutrinos from the center of the Sun. In this work the data taken from 2007 to 2022 by ANTARES, a neutrino telescope located in the Mediterranean Sea, have been used to perform an indirect search for dark matter towards the direction of the Sun. The properties of the incoming neutrino events are reconstructed using the standard algorithms developed in the Collaboration but also with a new Machine Learning tool, aimed to improve the reconstruction accuracy for neutrino energies below 200 GeV, used for the first time in this kind of searches. All-flavor neutrino interactions are also considered now in the analysis. An unbinned maximum likelihood approach is used to determine the sensitivity to the spin-dependent and spin-independent WIMP scattering cross-section, for WIMP masses from 50 GeV/c$^2$ to 10 TeV/c$^2$ and for three different annihilation channels.
The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is a 26-ton gadolinium-doped water Cherenkov detector situated 100 meters downstream in Fermilab's Booster Neutrino Beam. ANNIE’s main physics goal is to measure the final state neutron multiplicity of neutrino-nucleus interactions. This measurement will improve our understanding of these complex interactions and help reduce the associated systematic uncertainties, thus benefiting the next generation of long-baseline neutrino experiments. ANNIE has several years of beam data. This poster covers the initial phases of event reconstruction and characterization of neutron multiplicity as a function of momentum transfer. Techniques, such as ringing imaging to extract muon vertex and other methods for energy reconstruction, are discussed.
Although the standard neutrino oscillation process induced by neutrino mass is well-established, there may be second-order contributions to this phenomenon from physical mechanisms beyond non-zero neutrino masses that could modify the standard framework. In this study, we systematically evaluate DUNE's capabilities to observe such beyond-standard oscillation (BSO) effects, assessing its ability to distinguish between different BSO hypotheses by varying the size of the effects. The BSO hypotheses considered in this analysis include neutrino decay (visible or invisible), non-standard interactions, violation of the equivalence principle, and quantum decoherence. Our analysis also quantifies the potential distortions that can suffer the measured value of the CP-violating phase parameter, $\delta_{CP}$, when fitted with the wrong BSO hypothesis. We note that the latter even could happen for cases when the BSO mechanisms can be hardly discriminated among them (the true one from the theoretical hypothesis).
Neutrino oscillation provides a unique window in exploring physics beyond the standard model (BSM). One such scenario is quantum decoherence in neutrino oscillation which tends to destroy the interference pattern of neutrinos reaching the far detector from the source. In this poster, I will present the study of the decoherence in neutrino oscillation in the context of the ESSnuSB experiment. We consider the energy-independent decoherence parameter and derive the analytical expressions for P$_{\mu~e}~$ and P$_{\mu\mu}~$ probabilities in vacuum. We have computed the capability of ESSnuSB to put bounds on the decoherence parameters namely, $\Gamma_{21}~$ and $\Gamma_{32}~$ and found that the constraints on $\Gamma_{21}~$ are competitive compared to the DUNE bounds and even better than the T2K and MINOS ones. We have also investigated the impact of neutrino decoherence in the measurement of the Dirac CP phase $\delta_{\rm CP}~$ and concluded that the $\delta_{\rm CP}~$ measurement of ESSnuSB is robust even in the presence of decoherence.
It is well known that the presence of Earth matter affects the neutrino oscillations through the charged and neutral current (NC) interactions, facilitated by W and Z bosons, respectively. In order to explore beyond Standard Model NC interactions, an additional $Z^\prime$ gauge boson can serve as a mediator for the interactions between matter and neutrinos. In our work, we examine light $Z^\prime$ with mass $\leq 10^{-16} $ eV, which could mediate the force between the matter in the Sun and neutrinos on Earth, referred to as the long-range force (LRF). We investigate the sensitivity of future long-baseline neutrino experiments, P2SO and T2HKK, to constrain the LRF. Specifically, our objectives are to examine the ability to establish bounds on the LRF parameters, the impact of LRF on the measurement of standard oscillation parameters, and the capacity to constrain the mass of the new gauge boson and the value of the new coupling constant responsible for LRF due to matter density in the Sun. Our analysis reveals that among various neutrino experiments, the P2SO experiment is expected to provide the most stringent bounds on the LRF parameters, including the mass of the new gauge boson and the value of the new coupling constant. Furthermore, our findings demonstrate that LRF has significant effects on the determination of standard neutrino oscillation parameters $\theta_{23}$ and $\delta_{\rm CP}$, and found that the precision of $\Delta m^2_{31}$ remains unaffected by the presence of LRF in both P2SO and T2HKK.
Micro-structured units have been utilised in the KATRIN experiment to study the main spectrometer background, reflecting the significance of background mitigation possibilities in an experiment focused on measuring the absolute mass scale of neutrinos with exceptional sensitivity.
The prevalent background model is characterised by the ionisation of highly excited states originating from radioactive decays within the inner surface, with some of these states undergoing ionisation within the sensitive fluxtube volume, producing background electrons.
Furthermore, the incorporation of micro-structures holds promise for enhancing the sensitivity of the forthcoming detector upgrade of the KATRIN experiment, known as TRISTAN.
The TRISTAN detector upgrade marks the next stage in the KATRIN experiment's evolution, aiming to probe for a sterile neutrino at the keV scale by analysing its effect on the tritium beta spectrum.
Of particular concern are beta electrons that experience scattering upon encountering the golden rear wall of the experiment before reaching the detector. This phenomenon introduces distortions in the observed spectrum, demanding strategies to mitigate such effects to achieve the desired sensitivity levels.
To tackle this issue, various configurations of micro-structured rear walls are under scrutiny via Geant4 simulations. These simulations seek to pinpoint an optimal solution capable of minimizing the influence of scattered beta electrons on the measured spectrum.
The findings of these investigations are showcased in this poster, resulting in an enhanced background model and the identification of the optimal micro-structure unit, delineating shape parameters and material selection tailored for TRISTAN.
This work is supported by the Helmholtz Association and by the Ministry for Education and Research BMBF (grant numbers 05A23PMA, 05A23PX2, 05A23VK2, and 05A23WO6).
The Short-Baseline Neutrino program in Fermilab aims to resolve the nature of the low-energy excess events observed in LSND and MiniBooNE, and analyze with unprecedented precision neutrino interactions with argon. These studies require reliable estimate of neutrino cross sections, in particular for charged current quasielastic scattering (CCQE). In arxiv:2312.13369 (to be published in Phys. Rev. D), we report updates of the NuWro Monte Carlo generator that, most notably, bring the state-of-the-art spectral functions to model the ground state properties of the argon nucleus, and improve the accuracy of the cross sections at low energies by accounting for the effects of the nuclear Coulomb potential. We discuss these developments in the context of electron and neutrino interactions, by comparing updated NuWro predictions to experimental data from Jefferson Laboratory Hall A and MicroBooNE. The MicroBooNE CCQE-dominated data are described with the $\chi^2$ per degree of freedom of 0.7, compared with 1.0 in the local Fermi gas model. The largest improvement is observed for the angular distributions of the produced protons, where the $\chi^2$ reduces nearly by half. Being obtained using the axial form factor parametrization from MINERvA, our results indicate a~consistency between the CCQE measurements in MINERvA and MicroBooNE.
The PROSPECT, STEREO, and Daya Bay experiments have provided world-leading results regarding the detection of reactor-produced antineutrinos. PROSPECT and STEREO have made short-baseline (~10m) measurements of antineutrinos from highly enriched uranium (HEU) research reactors where over 99% of the antineutrino flux comes from $^{235}$U. The Daya Bay experiment has studied antineutrino emission at low-enriched uranium (LEU) power reactors that use a mixture of fissile isotopes, with detectors spanning a much larger baseline from the reactor cores (~2km). All three experiments have performed independent searches for sterile neutrino oscillations, excluding different regions of oscillation phase space. The PROSPECT collaboration has recently implemented new analysis event reconstruction techniques into their analysis resulting in a multi-period dataset marked by a significant enhancement in statistical power and improved signal-to-background ratios providing greater sensitivity for the search of sterile neutrinos. In addition, a new collaborative effort, utilizing the final data sets from all three experiments, aims to improve the precision of the search for light sterile neutrinos beyond what would be achievable by each experiment individually. This presentation reports the final search for eV-scale sterile neutrinos with the final PROSPECT-I data set, as well as the current status of the joint oscillation analysis between these experiments.
Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment located in southern China. The primary goal of JUNO is to determine the neutrino mass ordering and measure several neutrino oscillation parameters to sub-percent precision by measuring the oscillated reactor antineutrino spectrum at $\sim52.5$ km from eight nuclear reactors. Selection of the reactor IBD signal with high efficiency and accuracy is key to measuring the oscillated reactor antineutrino spectrum. This poster presents a box-cut method to separate the IBD signal from background, and the muon-veto strategy effect on background. The resulting IBD signal and background rates and uncertainties will be presented.
The Jiangmen Underground Neutrino Observatory (JUNO), currently under construction in China, will be a multi-kton liquid scintillator detector with a unique potential to perform a real-time measurement of solar neutrinos well below the few MeV threshold typical of Water Cherenkov detectors. JUNO’s large target mass and excellent energy resolution are prerequisites for reaching unprecedented levels of precision.
In this poster, we report the JUNO sensitivity to 7Be, pep, and CNO solar neutrinos that can be obtained via a spectral analysis. Different scenarios of the scintillator radiopurity are considered, ranging from the most optimistic one, which corresponds to the radiopurity levels achieved by the Borexino detector, up to the minimum requirements needed to perform the neutrino mass ordering determination with reactor antineutrinos. In most scenarios, JUNO will be able to improve the current best measurements on 7Be, pep, and CNO solar neutrino fluxes, with relevant impact for the understanding of the solar metallicity problem.
JUNO’s Sensitivity to Geoneutrinos
Cristobal Morales Reveco$^{1,2,3}$ on behalf of JUNO collaboration
1. GSI Helmholtzzentrum für Schwerionenforschung GmbH, Germany
2. RWTH Aachen University, Germany
3. Forschungszentrum Jülich GmbH, Germany
The Jiangmen Underground Neutrino Observatory (JUNO) is an experiment being built in China, which consists of a 20 kton liquid scintillator detector. The main objective of the experiment is to determine the neutrino mass ordering by measuring reactor antineutrinos at a 53 km baseline. The experiment is also expected to have a high sensitivity to geoneutrinos: electron antineutrinos from natural radioactivity decays from 238U and 232Th in the Earth. The radiogenic heat released in these decays is in a well established relationship with the amount of geoneutrinos. Thus, the measurement of geoneutrino flux can provide an insight on the Earth's energy budget. Even more, distinguishing the signal coming from the Earth's mantle is a key feature which can unveil its convection scheme and contribution to the total radiogenic heat. Within the first year of data taking, JUNO will be able to exceed the precision of the existing results from Borexino and KamLAND experiments. With increased statistics, JUNO will be able to measure Uranium and Thorium components of the geoneutrino flux individually, and to establish their ratio, yet another important parameter for the geoscience community, giving insights about the Earth's formation process.
The poster will be focused on the geoneutrino's sensitivity study at the JUNO experiment, reporting the latest expected precision of measuring the total and independent contributions of geoneutrinos from Uranium and Thorium.
The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator detector that will be located 650 m underground in the south of China. One of the main goals of the experiment is to determine the neutrino mass ordering. With energy resolution of 3% at 1 MeV, an optimized baseline of 52.5 km, and using electron antineutrino data from eight nuclear reactors, JUNO can determine neutrino mass ordering with a median significance level of $3\sigma$ after about six years of data taking. This poster is dedicated to the details of the JUNO neutrino mass ordering sensitivity analysis.
The KATRIN experiment aims to measure the neutrino mass by precision spectroscopy of tritium β-decay. Recently, KATRIN has improved the upper bound on the effective electron-neutrino mass to 0.8 eV/c² at 90% confidence level [1] and is continuing to take data for a target sensitivity of better than 0.3 eV/c².
In addition to a non-zero neutrino mass, there are other tensions in the neutrino and dark matter sector that call for an extension of the Standard Model. Interactions between neutrinos and dark matter could potentially resolve several of these tensions, and there are hints of their existence [2]. This contribution takes a closer look at the dark MSW effect [3] as a possible interaction mechanism, which modifies the dispersion relation of the neutrinos through interaction with a dark background field. The ultra-precise measurement of the tritium β-spectrum at KATRIN could reveal unique signatures of these modifications.
This poster provides an introduction to the dark MSW effect and its impact on the β-spectrum. First sensitivity estimates and an outlook on the dark MSW searches with KATRIN are discussed.
[1] KATRIN Collab., Nat. Phys. 18, 160–166, 2022.
[2] D. Hooper, M. Lucca, Phys. Rev. D 105, 103504, 2022.
[3] G. Huang, W. Rodejohann, Nucl. Phys. B 993, 116262, 2023.
The Karlsruhe Tritium Neutrino (KATRIN) experiment probes the effective electron anti-neutrino mass by a precision measurement of the tritium beta-decay spectrum near the endpoint.
A world-leading upper limit of $0.8 \,$eV$\,$c$^{-2}$ (90$\,$% CL) has been set with the first two measurement campaigns.
New operational conditions for an improved signal-to-background ratio, the steady reduction of systematic uncertainties and a substantial increase in statistics allow us to expand this reach.
This poster displays the latest KATRIN results and provides insight into the neural network approach used to perform the computationally challenging analysis.
This work received funding from the European Research Council under the European Union Horizon 2020 research and innovation programme, and is supported by the Max Planck Computing and Data Facility, the Excellence Cluster ORIGINS, the ORIGINS Data Science Laboratory and the SFB1258.
Light sterile neutrinos with a mass at the eV-scale could explain several anomalies observed in short-baseline neutrino oscillation experiments. The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to determine the effective electron anti-neutrino mass via the kinematics of tritium beta-decay. The precisely measured beta-spectrum can also be used to search for the signature of light sterile neutrinos.
In this poster we present the status of the light sterile neutrino analysis of the KATRIN experiment. The analysis contains data from the first five measurement campaigns and the obtained sensitivity is compared to current results and anomalies in the field of light sterile neutrinos.
This work received funding from the European Research Council under the European Union Horizon 2020 research and innovation programme, and is supported by the Max Planck Computing and Data Facility, the Excellence Cluster ORIGINS, the ORIGINS Data Science Laboratory and the SFB1258.
The IceCube Neutrino Observatory is located at the geographic South Pole instrumenting a cubic kilometer of deep glacial ice with 5,160 digital optical modules on the main array to detect Cherenkov light. The DeepCore sub-detector is a denser in-fill array that gives a lower energy threshold where we can study neutrino oscillations using atmospheric neutrinos with energies of 5-100 GeV. Precisely reconstructing neutrino energy and arrival direction is critical to constraining oscillation parameters. Convolutional neural networks are employed for precise and fast event reconstructions. In this contribution, using IceCube data collected from 2012 to 2021, including the latest improvements in reconstruction, selection, detector calibration, and treatment of systematic uncertainties, we present our most recent measurement of sin^2(\theta_{23}) and \Delta m^2_{32}.
Super-Kamiokande (SK), a 50 kton water Cherenkov detector in Japan, is observing neutrinos from various natural sources. SK studies the effects of both the solar and terrestrial matter density on neutrino oscillations: a distortion of the solar neutrino energy spectrum would be caused by the edge of the Mikheyev-Smirnov-Wolfenstein resonance in the solar core, and terrestrial matter effects would induce a day/night solar neutrino flux asymmetry. In this poster presentation, we overview the latest solar neutrino results using the data including the SK-Gd era, for example, the precise measurement of 8B solar neutrino flux, its energy spectrum, and oscillation parameters. In addition to them, we also present the time variation of observed solar neutrino flux and a possible correlation between the neutrino flux and the solar activity.
The Japanese Spallation Neutron Source (JSNS) at J-PARC can provide an intense source of light new particles. We study the sensitivity of existing neutrino detectors to the decay in flight of light scalars, axion-like-particles, and heavy neutral leptons produced in pion and kaon decay at JSNS. We consider the near detector of the T2K experiment, ND280, where the fast, magnetized, gaseous argon chambers can be used to look for low-energy charged tracks in coincidence with the JSNS beam pulse and direction. For final states with muons and charged pions, we also consider the liquid-scintillator detectors of the J-PARC Sterile Neutrino Search at the JSNS (JSNS$^2$) experiment, exploiting the double- and triple-coincidence nature of the signal. Finally, we also comment on the KOTO kaon detector and the possibility of looking for diphoton final states in association with JSNS beam pulses. The combination of these setups has the potential to improve existing limits by over an order of magnitude in some regions of parameter space, encouraging further study on data acquisition and background rejection by the experimental collaborations.
Jiangmen Underground Neutrino Observatory (JUNO), located in the southern part of China, will be the world’s largest liquid scintillator (LS) detector upon completion. Equipped with 20 kton LS, 17612 20-inch PMTs and 25600 3-inch PMTs in the central detector (CD), the primary goal of JUNO is to determine the neutrino mass ordering, by precisely measuring the oscillation energy spectrum of anti-neutrinos from reactors. One of main challenges of JUNO is the unprecedented energy resolution requirement. The charge smearing of single photoelectron for PMTs is one of the dominant contributing factors to the energy resolution in JUNO. This poster will present a achine-Learning-based method to reconstruct the number of photoelectrons for PMT waveforms and describe how it can be applied to JUNO to partially mitigate the impact of PMT charge smearing and improve the energy resolution.
The Jiangmen Underground Neutrino Observation (JUNO), located at Southern China, is a multi-purpose neutrino experiment that consist of a 20 kton liquid scintillator detector. The primary goal of the experiment is to measure the neutrino mass ordering (NMO) and measure the relevant oscillation parameters to a high precision. Atmospheric neutrinos are sensitive to NMO via matter effects and can improve JUNO’s total sensitivity in a joint analysis with reactor neutrinos, in which a good capability of reconstructing atmospheric neutrinos are crucial for such measurements.
In this poster, we present a machine learning approach for the particle identification of atmospheric neutrinos in JUNO. The method of feature extraction from PMT waveforms that are used as inputs to the machine learning models are detailed. Two independent strategies of utilising neutron capture information are also discussed and compared. Preliminary results based on Monte-Carlo simulations will also be presented. We demonstrate that using the machine learning-based approach shows good potential in future physics measurements.
Super-Kamiokande has observed $^8$B solar neutrino elastic scattering on electrons with recoil electrons at kinetic energies as low as 3.49 MeV to study neutrino flavor conversion within the sun. At SK-observable energies, these conversions are dominated by the Mikheyev–Smirnov–Wolfenstein effect. An upturn in the electron survival probability in which vacuum neutrino oscillations become dominant is predicted to occur at lower energies, but radioactive background increases exponentially with decreasing energy. New machine learning approaches provide substantial background reduction below 3.49 MeV such that statistical extraction of solar neutrino interactions becomes feasible. Measurements of the solar neutrino flux in this energy region using a boosted decision tree for event selection will be presented.
China JinPing Underground Laboratory (CJPL) is an underground laboratory with 2800 meters rock overburden and is ideal to carry out experiment for rare-event searches. Cosmic muons and muon-induced neutrons present an irreducible background to both solar neutrino and neutrinoless double beta decay experiment at CJPL. A precise measurement of the cosmic-ray background of CJPL would play an important role in the future experiments. Using a 1-ton liquid scintillator detector for the Jinping Neutrino Experiment(JNE), we give a measurement of cosmic muon flux and cosmogenic neutron production in liquid scintillator detector at CJPL. This study provides a clear understanding of cosmic-ray background at deep underground laboratory.
Kaon production cross sections provide an important constraint on $K^+$ production by atmospheric neutrinos in current and future proton decay searches. Modern neutrino-nucleus event generators largely depend on theoretical models for the descriptions of backgrounds due to kaons and need to be verified by measurements.
We search for $K^+$ production in charged-current neutrino interactions inside the scintillator-based fine-grained detector of the T2K experiment. The event rate for these processes is low compared to pion production channels because of Cabibbo suppression and the relatively large kaon mass. T2K measures this process at low neutrino energies close to the threshold for strangeness production where existing measurements from bubble chambers have limited statistics. Events with a $K^+$ are identified in T2K by studying the energy deposition of tracks in the Time Projection Chamber. This poster will show the latest results for the selected kaon sample together with comparisons to different models. It will also discuss the method used to estimate the backgrounds and evaluate a one-bin cross section in the restricted phase-space.
The KM3NeT/ORCA detector (Oscillation Research with Cosmics in the Abyss), currently under construction, is deployed at 2450m depth in the Mediterranean Sea, near Toulon, France. Its primary scientific goal is to determine the Neutrino Mass Ordering. ORCA is an array of Digital Optical Modules, spheres that host 31 photomultiplier tubes, tied together in vertical structures (the Detection Units -DUs), which are anchored on the seabed. Such an array configuration can detect neutrino events from the Cherenkov radiation emitted by the secondary particles of neutrino interactions in the abyssal depths of the Mediterranean Sea.
A measurement of the atmospheric muon neutrino flux in the energy range between 1 GeV and 100 GeV is presented in this work, using data collected with the 6-DU configuration of KM3NeT/ORCA (KM3NeT/ORCA6). The data analyzed corresponds to a period of almost one and a half years. The selection of a high-purity sample of atmospheric neutrino events, using a Machine Learning classifier (Boosted Decision Tree), is presented. An unfolding scheme, used to obtain an estimation of the atmospheric muon neutrino flux in bins of energy is shown. Finally, a detailed study of the impact of the systematic uncertainty sources in the measurement is also presented. This measurement illustrates the ability of the KM3NeT/ORCA detector to provide experimental information at an energy region in which only few measurements exist by other experiments, even with an early-stage detector configuration.
Electron-neutrino charged-current interactions on iodine have been proposed for solar and supernova neutrino detection, owing to the large predicted cross section. Using a 185-kg NaI[Tl] array, COHERENT has measured the inclusive electron-neutrino charged-current cross section on ${}^{127}$I with pion decay-at-rest neutrinos produced by the Spallation Neutron Source at Oak Ridge National Laboratory. The measured inclusive cross section of 9.2$^{+2.1}_{−1.8} \times 10^{−40}$ cm$^2$ is roughly 41% lower than predicted using the MARLEY event generator with a measured Gamow-Teller strength distribution. The neutron-emission channel appears to be a significant source of disagreement between results and predictions, in agreement COHERENT data of charged-current neutrino-induced neutron production on lead, indicating further improvements are needed in the modeling on low-energy neutrino interactions with heavy nuclei. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
ProtoDUNE Single-Phase was a 770 ton liquid argon time projection chamber detector. It was DUNE's first full-scale engineering prototype and operated from 2018-2020. It took test beam data of charged hadrons at momenta of 0.3-7 GeV/c in 2018, including data of positively charged kaons at high GeV-scale momenta. A total inelastic cross section was measured using these test beam kaons with the thin-slice method, which artificially divides the detector into slices where the particle either interacts in or passes through. The cross section data can help inform modeling uncertainties for final state and secondary interactions used in neutrino and nucleon decay analyses. The following poster will show the event selection, analysis methods, and final extracted cross section.
Measurements of electron neutrino charged-current interactions on Argon from 10-50 MeV are few but are important for future experiments and theoretical modeling of nuclei. Knowledge of the cross section at these energies will be critical in the event that the upcoming Deep Underground Neutrino Experiment (DUNE) observes neutrinos from a galactic supernova. Uncertainties on the cross sections will impact what can be concluded about both the dynamics of supernovae and the properties of neutrinos. Differential cross sections will also provide relevant data for ongoing theoretical work on modeling the transitions between nuclear states. The COHERENT collaboration is currently constructing a 750 kg single-phase liquid argon scintillator detector to study neutrinos coming from the Spallation Neutron Source (SNS) located at Oak Ridge National Laboratory (ORNL). In addition to producing a high-intensity flux of neutrons, the SNS also emits an intense source of neutrinos coming primarily from pion decay-at-rest. These neutrinos are emitted at an energy well matched to the regime of interest (10-50 MeV).This poster will discuss the status and timeline of the future 750 kg liquid argon scintillator detector along with a discussion on various aspects of the measurement.
Neutrino-Induced Neutrinos (NINs) are neutrons produced as a result of the interaction between neutrinos and nuclei. NINs are central to supernova early warning systems such as the Helium and Lead Observatory (HALO) and also appear as background in accelerator-based neutrino experiments. The occurrence of NINs affects the measurement of neutrino interaction rate (cross-section). In $2015$, the COHERENT collaboration deployed a detector at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) to measure NINs production in lead (Pb). The detector — referred to as the neutrino cube (nube) — was designed using ~$900$ kgs of cast lead and 4 liquid scintillators detectors. Despite the meticulous design and execution of the nube experiment, the data obtained yielded NINs rate that was a factor of $3$ lower than predictions. The discrepancies between the experimental observations and theoretical predictions underscore the potential for groundbreaking discoveries in nuclear physics. To study these unexpected findings, we proposed deploying a prototype Cerenkov detector as a precursor to a larger neutrino detector initiative.
In July $2023$, we successfully deployed a Cherenkov prototype detector at the Neutrino Alley, a basement corridor, at the SNS at ORNL. The prototype consists of Pb glass weighing ~$40$ kgs, $2$ photomultiplier tubes, and no shielding. We collected about $12$ terabytes of beam-on data with additional beam-off data. Our detector measures Cherenkov radiation facilitating a more comprehensive analysis of the electromagnetic component of charged-current neutrino interactions on $^{208}$Pb. The initial analysis and implications from the prototype will be presented. Plans for $2024$ deployment of a multi-array Pb glass detector at the SNS will also be presented.
The SNO+ experiment is a large multi-purpose neutrino detector, currently filled with liquid scintillator. For the first time in a single experiment, SNO+ is able to measure the neutrino oscillation parameters θ₁₂ and Δm²₂₁ simultaneously through both reactor anti-neutrinos and Boron-8 solar neutrinos. This poster demonstrates the latter approach, with an analysis of scintillator phase data. A Bayesian statistical approach via Markov Chain Monte Carlo is used, allowing for the simultaneous fitting of the oscillation parameters, Boron-8 neutrino flux, background components with constraints, and floating systematics. A sensitivity study shows that this measurement is statistics-limited, and precision could be improved by a factor of two with two years of livetime, assuming the same backgrounds and selections.
Current and future accelerator neutrino oscillation experiments need neutrino interaction models with smaller systematic uncertainties to resolve much of delta CP phase space. Final state interactions (FSI) and scattering off of correlated nuclei (2p2h) are poorly understood processes that currently contribute large uncertainties to leading models. These processes have proven difficult to study because they often produce relatively low energy nucleons. Protons up to about 100 MeV are below the detection threshold of some accelerator neutrino detectors, and neutrons are usually discounted as undetectable.
This poster presents a measurement of the multi-neutron antineutrino cross section at low available energy using the MINERvA detector at Fermilab. This interaction channel is particularly sensitive to FSI and 2p2h interactions. A sideband-driven background constraint that greatly reduces uncertainties on the result will be presented. The measured cross section is compared to GENIE v3 models with different FSI treatments and the SuSA model's 2p2h predictions.
The most powerful technique for directly studying the absolute neutrino mass is spectroscopy of beta-decay electrons at the endpoint of the spectrum. Project 8 has pioneered a new frequency-based method, cyclotron radiation emission spectroscopy (CRES), and intends to reach a sensitivity of 40 meV/c$^2$.
Replacing the traditional molecular T$_2$ with atomic T is key to this sensitivity; free from rovibrational energy broadening, atomic T boosts sensitivity 10-30x over a similar molecular experiment. Since tritium atoms recombine into molecules on contact with (most) surfaces, magnetic confinement is key to cooling, slowing, and storing the atoms.
Project 8's atomic system begins with production of a high flux ($>10^{19}$ s$^{-1}$) of hot atoms in a 2500 K tungsten capillary. Initial cooling to $\sim$ 30 K follows, using surface collisions. Atoms are then captured in a magnetic evaporative cooling beamline (MECB), which will evaporate away internal energy in the beam while simultaneously converting the forward beam momentum into internal energy for removal by evaporation. This section may be augmented by a cold buffer gas or rotating magnetic elements. Finally, the cold and slow beam of atoms will be guided through a small opening into a > 10 m$^3$ magneto-gravitaitonal atom trap. Sensitivity calculations show we need a density of $10^{17}-10^{18}$ m$^{-3}$, and the trap height sets a maximum temperature of $\sim$ 1 mK. A high-order multipole magnet (100-1000 poles) will confine the atoms radially and at the bottom, leaving the top of the trap open so that excess electrons escape. Compatibility with CRES imposes several coupled requirements on the magnetic design, so joint CRES-atomic design is a major focus of the collaboration.
This contribution will highlight the present status of Project 8's calculation, simulation, and prototyping work on the atomic system and show how these efforts support our design sensitivity to the absolute neutrino mass.
Producing 20,000 tons of ultra-pure liquid scintillator poses one of the most challenges for the Jiangmen Underground Neutrino Observatory (JUNO). The three components of the liquid scintillator—linear alkylbenzene (LAB), 2,5-diphenyloxazole (PPO), and 1,4-bis(2-methylstyryl) benzene (bis-MSB)—do not meet the strict radioactive content standards upon purchase from suppliers, necessitating the implementation of purification stages. To address this issue, a comprehensive on-site liquid scintillator production and purification system that incorporates several facilities was developed and constructed. The crucial task of purifying PPO and bis-MSB is assigned to the mixing system. This process begins with dissolving PPO and bis-MSB in LAB to create a highly concentrated master solution, subsequently decontaminated of radioactivity through comprehensive acid extraction and filtration processes. Following purification, the master solution undergoes online dilution to produce the liquid scintillator, subsequently transported to the underground laboratory. This poster aims to elucidate the mixing and purification processes of the master solution, detailing the composition of raw materials and radioactive content specifications, as well as the design, parameters, and distinctive construction features of the mixing system, while highlighting the successes of joint commissioning efforts. Results from joint commissioning have demonstrated that this methodology significantly reduces the radioactive content of the master solution by two orders of magnitude, marking a considerable advancement for JUNO.
With its unprecedented sensitivity to MeV-scale neutrinos, the Jiangmen Underground Neutrino Observatory (JUNO) will play an essential role in the emerging field of multi-messenger astronomy, especially in capturing next galactic core-collapse supernova (CCSN). Two real-time monitoring systems have been designed to detect the forecasted burst of neutrinos from a CCSN in JUNO. Here we present a dedicated CCSN monitoring system and its sensitivity to supernova neutrinos including a variety of supernova models. Assuming a yearly false alert rate, JUNO expects to be sensitive to neutrinos from a 30 $M_\odot$ progenitor up to 370 (360) kiloparsecs, with normal (inverted) mass ordering. The possibility to boost the CCSN sensitivity will be presented, including the one to low energy all-flavour neutrino events, made accessible with JUNO’s Multi-messenger trigger system, which aims to reduce energy thresholds to approximately 20 keV.
Low-temperature calorimeters have demonstrated significant efficacy in probing rare phenomena such as neutrinoless double beta decay and dark matter. Despite the impressive energy resolution these massive calorimeters achieve, the physics sensitivity reach is constrained by background radioactivity in these experiments. One approach to address this limitation involves implementing event-by-event background rejection through simultaneous readout of phonon and photon signals from scintillating crystals. Our current efforts focus on developing sensitive optical-photon detectors capable of capturing faint scintillation light in low-temperature calorimeters. We employ a pioneering Iridium/Platinum bilayer superconducting transition-edge-sensor (TES) technology, operating at temperatures below 40 mK, deposited on a large-area dielectric wafer (Si) serving as a photon absorber. These light detectors are ideal candidates for the next generation of calorimetric experiments involving thousands of channels. A multiplexed readout system is essential for this configuration to mitigate heat load into the cryostat and minimize surrounding radioactive materials. We are currently developing a frequency-domain multiplexing readout using TES bolometers, including designing a new resonator chip tailored to meet the bandwidth, size, and noise requirements of projects like CUPID (CUORE Upgrade with Particle IDentification). This resonator chip consists of ten superconducting resonators with characteristic frequencies in the MHz range and incorporates a SQUID (superconducting quantum interference device). Superconducting aluminum traces on Kapton backing transmit signals from the TESs and resonators at the 10 mK stage to the SQUID at a few hundred mK. Our ongoing work includes the characterization of optical photon detectors in terms of energy and timing resolution and the implementation of multiplexing readout in a ten-channel demonstrator.
NOvA is a long-baseline accelerator-based internationally collaborated neutrino experiment based in the USA. NOvA uses an intense neutrino beam produced at Fermilab’s accelerator complex to make physics measurements of neutrino oscillations, neutrino cross sections, and other high quality neutrino analyses. For its physics goals, NOvA uses two functionally-identical detectors. The Near Detector (ND) is situated at Fermilab, 1 km from the neutrino target and the Far Detector (FD) is located at Ash River, MN, a distance of 810 km from the neutrino source. The ND sees high intensity of the neutrino beam due to its close proximity to the neutrino target. This gives us a unique opportunity for high-precision neutrino cross-section measurements.
In this poster, we present our latest results of the muon antineutrino charge current inclusive cross section measurement in the NOvA ND. The new measurement is a triple differential cross section in antimuon kinematic phase-space and in the total energy of all observable final state hadrons, also known as the available energy. We also compare our data results to various neutrino generator predictions, for example, comparisons to GENIE, NuWro, NEUT, and GiBUU neutrino generators are presented.
The ICARUS T600 LArTPC detector successfully ran for three years at the underground LNGS laboratories, providing a first sensitive search for LSND-like anomalous electron neutrino appearance in the CNGS beam. After a significant overhauling at CERN, the T600 detector has been placed in its experimental hall at Fermilab, fully commissioned, and the first events observed with full detector readout. Regular data-taking began in May 2021 with neutrinos from the Booster Neutrino Beam (BNB) and neutrinos six degrees off-axis from the Neutrinos at the Main Injector (NuMI). Modern developments in machine learning have allowed for the development of an end-to-end machine learning-based event reconstruction for ICARUS data. This reconstruction folds in 3D voxel-level feature extraction using sparse convolutional neural networks and particle clustering using graph neural networks to produce outputs suitable for physics analyses. This poster will summarize the performance of a high-purity and high-efficiency end-to-end machine learning-based selection of muon neutrinos from the BNB and highlight studies of electromagnetic shower reconstruction from a neutral pion selection.
The DARWIN project aims to build and operate a next-generation observatory for dark matter and neutrino physics. The detector will feature a dual-phase time projection chamber with an active target of 40$\,$tonnes of liquid xenon (LXe), built underground with carefully selected materials. Its low-energy threshold and ultra-low background will enable the search for a wide range of neutrino interactions and properties: via electronic recoils off the LXe target, the flux of the low-energy pp, $^{7}$Be, $^{13}$N, $^{15}$O, and pep neutrinos can be measured; while a precise constraint of the $^{8}$B solar neutrino flux will be achieved by measuring coherent elastic neutrino-nucleus scattering (CEvNS) interactions. Given its large target mass, DARWIN will be sensitive to neutrinos coming from a supernova (SN) burst, within and beyond the Milky Way up to $\sim$70$\,$kpc. DARWIN will therefore participate in the SuperNova Early Warning System (SNEWS) both by listening for SN alerts as well as actively sending SN warnings to the network.
This contribution will cover the current DARWIN project design and neutrino physics reach of this next-generation LXe detector.
Systematic studies of core-collapse supernovae (CCSNe) have been conducted based on hundreds of one-dimensional artificial models (O'Connor & Ott 2011,2013; Ugliano et al. 2013, Ertl et al. 2015) and two-dimensional self-consistent simulations (Nakamura et al. 2015;2019, Burrows & Vartanyan 2020). We have performed three-dimensional magnetohydrodynamic simulations for the core-collapse of 16 progenitor models covering ZAMS mass between 9 and 24 solar masses. Our CCSN models show a wide variety of shock evolution, explosion energy, as well as multi-messenger signals including neutrinos. We present the dependence of the neutrino properties on the progenitor structure.
The decay-at-rest of charged kaons produces monoenergetic muon neutrinos with an energy of 236 MeV. The study of these neutrinos at short baselines allows us to constrain neutrino interactions. In this work, we study kaon decay-at-rest neutrinos at the MiniBooNE and JSNS2 experiments. We use data from these experiments to probe standard neutrino interaction cross-sections as well as non-standard interactions of leptons with strange particles. We also explore the reach of these experiments and future oscillation experiments to constrain these non-standard interactions. Finally, we discuss the synergy with data from other experiments in order to better constrain new physics in this sector.
Much has been learned about the deep Earth based on seismic measurements, combined with geophysical constraints and theories of Earth formation. However, such methods alone cannot directly resolve the full structure of the inner Earth, e.g. in terms of matter density, composition and temperature distributions. One open question in this realm concerns the nature and composition of two large-scale heterogeneities revealed by 3D seismology and known as large low-shear-velocity provinces (or LLVPs), that sit at the base of the mantle beneath the Pacific and Africa.
A renewed perspective on these questions may come from atmospheric neutrino oscillation tomography. For neutrinos crossing the Earth, distortions in the flavour oscillation patterns due to matter effects are expected in the energy range ~1-10 GeV, where the atmospheric neutrino flux is most abundant. Measuring the flavour, energy and angular distributions of such neutrinos provides sensitivity to a new observable of geophysical interest: the electron number density in the layers of matter traversed.
The upcoming generation of experiments detecting atmospheric neutrinos at the GeV scale, including DUNE, Hyper-Kamiokande and KM3NeT/ORCA, may therefore open new perspectives for neutrino oscillation tomography of the Earth. In order to explore their potential for probing asymmetric models of the Earth's mantle, we have developed a flexible simulation framework based on parameterized detector response functions and including for the first time a full 3D Earth model. Applying this framework, we investigate (i) the possibility of neutrino tomography to differentiate LLVP models consistent with current seismic data, and (ii) the combined sensitivity achievable with different detector configurations around the Earth.
The Jiangmen Underground Neutrino Observatory (JUNO) will be a 20-kiloton liquid scintillator detector, currently under construction in southern China. JUNO will be equipped with 17,612 20-inch photomultiplier tubes (PMTs) and 25,600 3-inch PMTs and aims to determine the neutrino mass ordering as the primary physics target by precisely measuring the energy spectrum of the reactor electron antineutrinos. For this physics objective, a high-quality signal and background separation as well as an optimized energy resolution are indispensable, and the event reconstruction is one of the key components to carry them out. We will present an event reconstruction algorithm that identifies the event vertex position, particle type, and energy. The tuning of this algorithm does not rely on simulation samples but utilizes the forthcoming calibration data, especially radioactive neutron source and cosmogenic spallation neutron events. This poster will cover the development scheme of the algorithm based on those calibration events, and expected performances of the vertex reconstruction, particle identification with the traditional pulse-shape discrimination technique, and energy reconstruction evaluated using the JUNO detector simulation.
Detecting neutrons from the interactions of MeV to GeV neutrinos promises to uncover previously hidden details of what is happening at the heart of the interaction and help to reconstruct precise (anti)neutrino kinematics. The newly upgraded near detector, close to the muon (anti)neutrino beam for the T2K experiment, includes a novel super fine-grained detector (Super-FGD), a 3D tracker capable of tagging neutrons from neutrino and antineutrino beam interactions. The primary goal of the near-detector upgrade is to reduce systematic uncertainties associated with neutrino flux and cross-section models for future studies of neutrino oscillations.
A key goal is the measurement of the cross section associated with the pionless charged-current quasielastic interaction of muon antineutrinos, producing a muon and one or more neutrons (CC0pi-n) with the beam operating in antineutrino mode. However, a fraction of the antineutrino beam in fact consists of muon neutrinos, and these can produce a neutron through additional nuclear effects. As such, muon neutrinos are an important background for the muon antineutrino CC0pi-n signal and it is vital to constrain these. The beam is currently being operated to produce muon neutrinos (neutrino mode) and this provides the perfect opportunity to measure the muon neutrino CC0pi-n cross section to place stronger constraints on nuclear effects.
This poster will discuss the detection of neutrons in the Super-FGD for CC0pi-n measurement in the muon neutrino beam, and the significance of the neutron data for the T2K, Super-Kamiokande and Hyper-Kamiokande experiments in discriminating between neutrino interaction generator models.
The goal of CONNIE (COherent Neutrino-Nucleus Interaction Experiment) is to detect reactor antineutrinos via the CE$\nu$NS (Coherent Elastic Neutrino Nucleus Scattering) channel using fully depleted high-resistivity CCDs (charge coupled devices) installed at about 30 meters from the core of the 3.8 GW Angra-2 nuclear reactor in Rio de Janeiro, Brazil. In 2021, The detector was upgraded with two Skipper-CCDs, becoming the first to deploy these type of sensors at a reactor, and lowering the detection threshold to a record 15 eV. We report new results from 300 days of data from 2021-2022, with an exposure of 18.4 g-days, including 95% C.L. limits on the CEvNS rate with Skipper-CCDs. Additionally, we present three BSM searches to illustrate the potential of Skipper-CCDs, namely: a limit on new neutrino interactions in simplified models with light vector mediators, a dark matter search by diurnal modulation yielding limits on DM-electron scattering, and a search for millicharged particles produced by reactors. We will discuss our current plans and ongoing efforts to increasing the detector mass.
New results from the DANSS experiment on the searches for sterile neutrinos are presented. They are based on 8.5 million inverse beta decay events collected at 10.9, 11.9, and 12.9 meters from the 3.1 GW reactor core of the Kalinin Nuclear Power Plant in Russia. Additional 0.8 million of antineutrino events collected in 2023 further improves the sensitivity for the sterile neutrino mixing parameter below 0.01 for a sterile neutrino mass around 1 eV. Obtained limits exclude practically all sterile neutrino parameters preferred by the recent BEST results for $\Delta m^2$ below 5 eV$^2$. The neutrino spectrum dependence on the 239Pu fission fraction is presented. It agrees with the predictions of the Huber-Mueller model. Using this dependence, the ratio of cross sections for 235U and 239Pu was extracted. It also agrees with the Huber-Mueller model and somewhat larger than in other experiments. The accuracy in the determination of the 239Pu fission fraction from the IBD positron spectra is estimated. The reactor power was measured using the IBD event rate during 7.5 years with a statistical accuracy of 1.5% in 2 days and with the relative systematic uncertainty of less than 0.5%. The neutrino oscillation analysis using the predictions for the absolute antineutrino flux from the reactor with a conservative systematic error of 5% excludes practically all sterile neutrino parameter space preferred by the recent BEST results as well as the best fit point of the Neutrino-4 experiment. The fraction of the reactor antineutrino yield with energies above 8 MeV is measured. Such antineutrinos are important for searches of neutrino coherent scattering.
In the ECHo experiment large arrays of low temperature metallic magnetic calorimeters (MMCs) enclosing Ho-163 are used for the high resolution measurement of the electron capture spectrum. The goal of the experiment is to achieve the sensitivity to detect an extremely small spectral shape distortion in the end point region due to a finite neutrino mass.
Thanks to the modular construction of the experiment, several phases have been foreseen. The first phase, ECHo-1K was designed to test the properties and reproducibility of MMCs with implanted Ho-163. With a small scale experiment a sensitivity on the effective electron neutrino mass 10 times better than the present limit of 150 eV/$c^2$ at 90% C.L. can be achieved.
At the same time, the preparation of large detector arrays and multiplexed readout for the ECHo-100k phase is on-going. Important milestones for detector fabrication, in particular related to Ho-163 implantation on wafer scale,have been reached. We present the status of ECHo-100k and discuss our perspectives for achieving a sensitivity at the 1 eV/$c^2$ level and below for the effective electron neutrino mass.
The recent detection of the coherent elastic neutrino-nucleus scattering (CEνNS) opens the possibility to detect neutrinos with small-size detectors and with different techniques, opening a new window to explore possible BSM physics.
The CEνNS process generates signals at the few-keV level, requiring sensitive detection technologies for its observation. The European Spallation Source (ESS) has been identified as the best possible site for the exploration this CEνNS process.
Within the NuESS program, two different detector approaches are currently under development at Donostia International Physics Center (DIPC). The GanESS project, a high-pressure gaseous time projection chamber (TPC) and the CoSI project, which employs cryogenic undoped CsI crystals.
These next-generation technologies will be capable of observing the process with lower energy threshold and better energy resolution than current detectors. In addition, the combination of these detectors will allow for a complete phenomenological exploitation of the CEνNS signal. In particular, these measurements will not be statistically limited due to the synergy between larger neutrino fluxes at the ESS and these improved detectors.
I will give an overview of the current status of NuESS with a focus on its short-term plans.
The ICARUS T600 Liquid Argon Time Projection Chamber (LArTPC) detector is the far detector of the Short Baseline Neutrino (SBN) Program located at Fermilab National Laboratory (FNAL). The data collection for ICARUS began in May 2021, utilizing neutrinos from the Booster Neutrino Beam (BNB) and the Neutrinos at the Main Injector off-axis beam (NuMI). The SBN Program has been designed to investigate the observed neutrino anomalies e.g. the former electron neutrino excess from the LSND experiment and the more recent MiniBooNE anomaly. To analyze collected neutrino data, we utilize two methods of event reconstruction: (1) the Pandora multi-algorithm approach to automated pattern recognition, and (2) an approach making use of machine learning (ML). With these reconstruction methods, we improve our identification and energy reconstruction of track-like and shower-like particles. These improvements give us greater precision and accuracy in our electron neutrino measurements. I will present an overview of the ML reconstruction, a selection of the electron neutrinos coming from the NuMI off-axis beam, and the future of electron neutrino analyses utilizing ML reconstruction at ICARUS.
Xenon-based detectors are powerful tools in the search for low energy signatures of new physics. Here we report experimental results that open up a new channel for rare event searches in these detectors: MeV-scale charged-current interactions on 136Xe nuclei. These interactions will populate low-lying 1+ excited states in 136Cs, which then relax to the ground state through the emission of characteristic gamma rays. We have performed measurements of γ rays produced by 136Xe(p,n)136Cs reactions, providing the first data on the gamma ray emission from the relevant excited states. We also identify two isomeric states with O(100)~ns lifetimes, which will create delayed-coincidence signatures in charged-current interactions that can be used to dramatically suppress backgrounds. These results could enable xenon-based detectors to perform background-free measurements of solar 7Be and CNO neutrinos, as well as achieve world-leading sensitivity to dark matter particles interacting with nuclei through new charged-current-like interactions.
No method for efficient detection of electron neutrino in MeV energy region has been established so far although there are interesting physics channels in the low energy such as measurement of supernova $\nu_e$, $\nu_e$ oscillation and $\nu_e$-nucleus interactions. Lead (Pb) has a novel potential as $\nu_e$ target. $\nu_e$ is expected to interact with Pb nucleus and produce an electron and neutrons. The interaction is exciting since the cross section is expected to be very large and the delayed coincidence method is available to reduce the backgrounds. Despite such the potential, experimental observation has not been made yet.
The Hg target of 3 GeV proton beam in J-PARC/MLF is a great source of neutrinos. Many $\pi^+$ are produced and stops in the target, and they decay to $\mu^+$. The $\mu^+$ also stops in the target and decay to $\nu_e$ with mean energy 30 MeV. We are preparing measurement of decay-at-rest $\nu_e$-Pb cross section measurement in the MLF experiment area. Major background sources are fast neutrons and gamma rays related to beam collision to the proton beam target. We performed some test measurements using small detectors to investigate properties of the backgrounds and to search for a good detector location in 2021 and 2022. Then we developed a prototype of a neutrino detector with 1 m [L] x 1 m [W] x 60 cm [H] scale, based on 4 mm thick lead planes and two different types of plastic scintillators with 10 cm and 1cm thickness. The prototype detector contains three layers of 1m x 1m x 4 mm lead planes with total weight of 136 kg as the neutrino target and 2 layers of the plastic scintillator planes with 1 cm thickness sandwiches the lead planes to identify the minimum ionizing electrons. 10 cm thick plastic scintillator bars with Gadolinium sheets also surround the lead and scintillator planes sandwich to measure electron energy and to detect neutrons. The prototype was constructed in the MLF experimental area and was tested in 2023. We started physics data taking to estimate the amount of background level in 2024.
In this presentation, we plan to report first results of the test measurement. We also discuss the possibility of the measurement of the neutrino cross section in future experiments.
The Taishan Antineutrino Observatory (TAO, also known as JUNO-TAO) is a satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO). The experiment consists of a ton-level liquid scintillator detector placed at 44 m from a 4.6 GWth reactor core of the Taishan Nuclear Power Plant. The main goal is to measure the reactor antineutrino spectrum with sub-percent energy resolution, providing a reference spectrum for JUNO as well as a benchmark for nuclear databases and other experiments. The detector design consists of a spherical acrylic vessel containing 2.8 ton gadolinium-doped liquid scintillator viewed by 10 m^2 Silicon Photomultipliers (SiPMs) with ∼50% photon detection efficiency and providing around 95% photon coverage. The expected energy resolution is better than 2% at 1 MeV. The detector will operate at -50◦C to mitigate the impact of SiPM dark noise. About 1000 reactor antineutrinos will be collected per day. The detector is under construction and a prototype detector has been assembled and tested. The detector operation is expected to begin as soon as 2024.
The Diffuse Supernova Neutrino Background (DSNB) is the integrated flux of neutrinos and antineutrinos emitted by all past supernovae in the observable Universe. It is yet to be observed.
In this regard, the Super-Kamiokande (SK) experiment has entered its gadolinium (Gd) era in 2020: the Gd-loading of the water tank enhances the capability to tag the inverse beta-decay neutron stemming from the interaction of a DSNB electronic antineutrino with a proton.
In this poster, I will present the model-dependent analysis developed for the DSNB search, and its results with the most recent SK data, with increased signal sensitivity owing to Gd-loading. I will also show how evidence for DSNB is within reach with the SK-Gd experiment.
The Deep Underground Neutrino Experiment (DUNE) is a cutting-edge international neutrino experiment under construction now in US, which uses Liquid Argon Time Projection Chambers (LArTPCs) as its main detector technology for particle identification on the far site in the SURF facility in South Dakota. The far detector (FD) modules will be able to detect longbeam neutrinos (generated by a source at the near site in FNAL) but also neutrinos from natural sources (like solar and cosmic rays). In this work, I am focusing on atmospheric neutrinos, created in Earth’s atmosphere by cosmic ray interactions. To determine the moving direction of an atmospheric neutrino, identifying its interaction vertex in the LArTPC is an essential first step to determine the distance the neutrino traveled before interacting, and hence make it possible to calculate its oscillation probability. I will present the performance of the reconstruction algorithm for the neutrino interaction vertex in the DUNE FD LArTPCs. Using a simulated sample of atmospheric neutrinos, I will show the current performance (resolutions and reconstruction efficiency) of the vertex reconstruction in the DUNE’s FD. I will also present my work on identifying failure points and improving the algorithm using deep learning techniques. Further development prospects will also be discussed.
The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kilo-tons liquid scintillator detector currently under construction in southern China. The primary goal of the experiment is to determine the mass hierarchy of the neutrino by analysing the energy spectrum shape of reactor antineutrino. That is why, the detector’s energy response is of paramount importance. In the JUNO detector, the liquid scintillator is seen by 17612 20-inch PMTs (Large PMT) and 25600 3-inch PMTs (Small PMT). The LPMT subdetector constitutes the main calorimeter with an excellent energy resolution but can be submitted to instrumental non-linearity for large signals. Unlike the LPMT, the Small PMT subdetector operates in a single photo-electron regime. This subdetector is essential to characterise the overall detector non-linearity. In this poster, we will present the status of the installation and the preliminary performances of the SPMT subdetector with more than 11000 channels tested during the first commissioning runs. In particular, we will report on the preliminary measurement of the electronic noise, PMT gain, and the charge resolution.
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long baseline neutrino experiment that will take place in the US. This experiment will feature in its first phase two Liquid Argon Time Projection Chambers (LArTPCs) with a volume of 17kt each. In addition to the accelerator neutrino program, the DUNE far detector will provide a unique opportunity to study atmospheric neutrinos with precision. Due to their wide distribution in energy E and large distance travelled L, atmospheric neutrinos allow to probe a wide range of E/L values and therefore can provide invaluable insights into the different parameters of the PMNS matrix. Moreover, the results obtained with this source of neutrinos will be complementary to the accelerator neutrino program of DUNE and the joint analysis will improve sensitivity, or contrarily raise tensions hinting at new physics. This poster will show a phenomenological study sensitivities to the oscillation parameters and the mass hierarchy from atmospheric neutrinos simulations in a DUNE-like setup.
DUNE is a long-baseline neutrino experiment that will use the new LBNF (Long-Baseline Neutrino Facility) neutrino beam sampled at the Near Detector complex (DUNE ND), 574 m downstream of the production target, and at the Far Detector complex, 1300 km away at the SURF laboratory at a depth of about 1.5 km. To assess the future performance of the DUNE Far Detector, full-scale prototypes of the DUNE FD modules have been implemented at the CERN Neutrino Platform facility, in Geneva, Switzerland. ProtoDUNE will help define the production and installation procedures for the DUNE Far Detector, and at the same time allow for physics measurements with the detector’s response to different charged particles from CERN’s H4-VLE Beam Line. The H4-VLE beam consists of tertiary electron, proton, muon, kaon, and pion beams with momentum ranging from 0.3 GeV/c to 7 GeV/c. Measurements of those particles can be exploited to determine the cross sections of interactions of charged particles in Liquid Argon. An initial run of ProtoDUNE was completed in 2018, with a second run being prepared for Summer 2024. In this poster, I will introduce the ProtoDUNE experimental setup and present pion candidate selection methods used for the 2 GeV/c beam momentum sample, which will enable future cross-section measurements in ProtoDUNE. Additionally, I will discuss results from fake data studies and comparisons of pion interactions using different event generators.
The NOvA (NuMI Off-Axis electron neutrino Appearance) experiment is a long-baseline neutrino oscillation experiment composed of two functionally identical detectors, a 300 ton Near Detector, and a 14 kton Far Detector separated by 809 km and placed 14 mrad off the axis of the NuMI neutrino beam created at Fermilab. This configuration enables NOvA's rich neutrino physics program, which includes measuring neutrino mixing parameters, determining the neutrino mass hierarchy, and probing CP violation in the leptonic sector. The NOvA Test Beam experiment deployed at Fermilab uses a scaled-down 30 ton detector to analyze tagged beamline particles. The beamline can select and identify electrons, muons, pions, kaons, and protons with momenta ranging from 0.4 to 1.8 GeV/c. Pions are an important component of the hadronic system in neutrino interactions and understanding how the detector responds to these particles is crucial. This poster will show preliminary results from studies of pion response in the NOvA Test Beam detector.
Spurred by a variety of neutrino oscillation anomalies, a strong interest has arisen in recent years in non-standard neutrino interactions (both active and sterile). The effects of such interactions have been also investigated within extensions of the standard cosmological model.
The work focuses on the possibility to characterize and constrain the parameter space of the so-called Majoron models of neutrino mass generation through new cosmological observables not explored so far, like polarization and cosmic birefringence. The study is developed through the use of the Quantum Boltzmann Equation (QBE) formalism (see Kosowsky 1996; Sigl and Raffelt 1993), a theoretical tool allowing us to track the evolution of particle number densities by taking into account correlations between particles with different discrete quantum numbers, like flavor or helicity.
We investigated the evolution of the cosmic microwave background (CMB) photons density matrix induced by the energy transfer between neutrino and photon mediated by a pseudoscalar particle (in both the limits of massless and massive), considering both tree-level diagrams and 1-loop corrections. The resulting Botlzmann hierarchy, written in terms of the CMB Stokes' parameters, shows a clear dependence on the parameters of the model, thus hinting at another probe of fundamental physics complementary to laboratory experiments.
The main equations resulting from this work provide two main effects: a modification in the optical depth of the cosmic fluid and a coupling between different polarization modes of the photon background.
The Project 8 experiment aims to probe the absolute neutrino mass through direct kinematic measurements of the tritium beta decay spectrum using cyclotron radiation emission spectroscopy (CRES). Non-uniformity of the magnetic field in the physics volume is expected to dominate the achievable energy resolution, and thus sensitivity.
CRES requires precise knowledge of the field through which an electron travels, but due to the electrons' high velocity, they would exit a region of flat field too rapidly to be observed. Therefore, we augment a carefully tuned uniform field with a magnetic bottle trap. Around the sides of the electron trap, a high-order multipole magnet adds a strong field only near the wall. This traps the cold tritium atoms whose decay provides the electrons for CRES.
This contribution details how, individually and in concert, the three elements of Project 8's magnetic field impact key performance parameters like electron trapping efficiency and energy resolution. By including all three fields and realistic manufacturing choices and tolerances in this integrated magnet program, we link field design choices directly to neutrino mass sensitivity.
The Deep Underground Neutrino Experiment (DUNE) international project, currently under construction, will enable an exciting program for precision neutrino physics and beyond. Two multidetector facilities will be exposed to the world's most intense neutrino beam: the Near Detector complex will measure the beam flux and composition 575 m downstream of the production target, at Fermilab; and the Far Detector complex, including up to four 17 kton modules utilizing LArTPC technology, will remeasure the beam 1300 km away, when installed about 1.5 km deep in the Sanford Underground Research Facility in South Dakota.
The combination of the high-intensity Long-Baseline Neutrino Facility (LBNF) beam with DUNE's highly-capable Near Detector and large-volume high-resolution Far Detector with low cosmic backgrounds opens up prospects for a rich program of Beyond the Standard Model (BSM) physics searches. These searches include discovery of new particles (sterile neutrinos, dark matter, heavy neutral leptons, etc.), precision tests of the neutrino mixing matrix including non-standard neutrino interactions, and the detailed study of rare processes (e.g. neutrino trident production). In this poster, we will present promising opportunities for BSM Physics probes with DUNE, and discuss their potential impact and outcomes.
The IceCube Neutrino Observatory consists of one cubic kilometer of Antarctic ice at the South Pole, which is instrumented with optical modules to detect Cherenkov light produced during neutrino interactions. The central lower region of the detector, known as DeepCore, has closely spaced optical modules that allow it to detect neutrinos with energies as low as a few GeV. We use the GeV-energy atmospheric neutrinos detected by IceCube DeepCore to search for neutrino decay, a phenomenon which is allowed in many grand unified theories beyond the Standard Model. While the decays of $\nu_1$ and $\nu_2$ are strongly constrained by supernova and solar neutrino data, atmospheric neutrinos offer an opportunity to search for the decay of $\nu_3$ using wide ranges of energies and baselines. In this contribution, we present a search for invisible decay modes of $\nu_3$ using a three-flavor neutrino oscillation framework in the presence of Earth matter effects.
The XENON collaboration, has used a series of xenon dual-phase time projection chambers (TPCs), to search for the first direct evidence of Dark Matter (DM) in the Universe. The latest generation experiment, XENONnT, operates in the LNGS underground facility in Italy, utilizing 5.9 tonnes of liquid xenon. With an unprecedented reduction in background level, XENONnT opens new avenues for investigating rare physical processes beyond DM. Among these searches, the study of two-neutrino double beta decay of Xe-136 has garnered interest due to its potential to provide insights into rare nuclear transitions. Precise measurement of the spectral shape of this process not only aids in constraining nuclear model predictions but also in probing physics beyond the Standard Model. This poster will cover the current status of the two-neutrino double beta decay of Xe-136 study with the XENONnT experiment.
The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment currently being constructed in China. JUNO uses a 20-kiloton liquid scintillator detector equipped with 17612 20-inch PMTs and 25600 3-inch PMTs. Its main physics goal is to determine the neutrino mass ordering and achieve precision measurements of oscillation parameters. Besides that, JUNO is capable of recording a large amount of data from neutrinos produced by the next galactic Core-Collapse Supernova (CCSN) burst, which can be used for both astrophysics and particle physics studies. In particular, JUNO will be sensitive to all neutrino flavours from a CCSN flux by different interaction channels. This poster outlines the selection strategies to identify the relevant neutrino interaction channels with the 20-inch PMTs, and presents a method for reconstructing the energy spectra of all types of neutrinos from CCSN events.
The ability of future accelerator-based neutrino experiments to set unprecedented constraints on all oscillation parameters, requires a solid understanding of neutrino cross sections. This is true especially for the most often selected signal of final state lepton and a single proton, and its background which could consist of processes with more than one final state proton. However, neutrinos are weakly interacting, and therefore measurements are statistically limited, making their model constraining very challenging. Nonetheless, neutrinos and the well-known electrons have a few similarities, such as the vector part of their interaction with the nucleus and many identical nuclear effects. In 𝑒4𝜈, we use electron-nucleus interaction measurements at various beam energies and target nuclei from the CLAS12 spectrometer at Jefferson Lab, Virginia, to test and constrain models of neutrino-nucleus interactions for their future use in oscillation experiments. Presented here for the first time a comparison between data and simulation used for neutrino experiments of the ratio between events with two protons and events with one proton and one neutron at the final state. These comparisons shed light on interesting nuclear effects.
Interaction generators for neutrinos are essential tools to predict the final states of neutrino interactions from atmospheric and accelerator sources. Those final states would be important input to quantify the relation between the visible energy in our detector and the neutrino energy, whose distribution is affected by oscillation. This understanding is crucial for experiments such as JUNO, DUNE, and Hyper-Kamiokande. GENIE is one of the neutrino generators that specialise in the GeV region. Much work is being done to tune GENIE models' parameters to obtain for the best description of experimental datasets. In addition, the parameters extracted from the tuning have very well motivated statistical uncertainties that will make the analyses more robust as based on better motivated inputs. Once the initial inputs are defined, it will be crucial to understand the how the uncertainties would affect the predictions. Reweighting is a powerful approach to propagate those model uncertainties through GENIE. There are many restrictions in the current reweight approaches, the main being that only a subset of parameters can be reweightable. This work aims to utilize the Professor tool to model GENIE as respondence functions. This approach unifies the workflow of tunning and reweight, allowing us to propage the uncertainty obtained from the tuning using a reweight infrastructure. This will enable us to do reweight all parameters, including previously unweightable parameters, e.g. hadronization parameters.
SoLAr is a future MeV-scale neutrino experiment planning for a near-term future detector at Boulby Underground Laboratory in the United Kingdom. It uses a shared anode plane with combined pixelated charge and light readout planned to enable tracking and calorimetric reconstruction using combined light and charge data, providing greater sensitivities to solar neutrinos and other MeV-scale neutrino interactions. The following poster shows the progress towards simulating and reconstructing solar neutrino interactions in a dual-readout detector. Focus will be placed on reconstruction techniques.
The Jiangmen Underground Neutrino Observatory (JUNO) has been primarily designed to determine the neutrino mass ordering by measuring the energy spectrum of neutrinos from two nuclear power plants, utilizing its exceptional energy resolution. JUNO employs a 20 kton liquid scintillator as the target substance in the central detector, with tens of thousands of 20-inch PMTs applied to achieve high photocathode coverage. Currently, the JUNO detector is under assembly, with about 30% 20-inch PMTs already installed and connected to the electronic readout. As part of the commissioning process, tests in the dark experimental hall have been conducted multiple times to assess the performance of the PMTs and the data-taking workflow. The poster will present an overview of the JUNO commissioning process and results from the aforementioned light-off tests, such as the dark count rates of installed PMTs and electronic noise levels. Moreover, the consistent PMT waveform reconstruction results from the FPGA in the front-end electronics and those from the offline algorithms will also be shown.
The unknown absolute scale of the neutrino mass remains an outstanding problem in astro and particle physics. Project 8 experiment seeks to measure the effective $anti-$neutrino mass $m_{\beta}$ with a sensitivity of $40~\text{meV}/c^2$ with the tritium endpoint method. To achieve this goal, Project 8 has pioneered the Cyclotron Radiation Emission Spectroscopy (CRES) technique. Adopting a four-phased approach, in Phase II Project 8 has recorded the first CRES tritium spectrum in a waveguide apparatus and extracted the first frequency-based neutrino mass limit. This milestone has established CRES as a promising method for direct neutrino mass measurement. In Phase II, Project 8 also performed high-resolution CRES spectroscopy on 83mKr conversion electrons. This source is widely used for low-energy particle detector calibration, with the K-32 conversion line at 17.8-keV being close to the tritium endpoint at 18.6-keV. Measurements of the 32-keV gamma energy and the Kr shell electron binding energies were conducted based on the high-resolution CRES frequency spectra of the 83mKr conversion electrons generated in the 32-keV isomeric transitions. Improved precision was achieved for the binding energies of the L1, L2, L3, M1, M2, M3 shell electrons in our measurements compared to the literature values. Those measurements pave the way for the high-resolution spectroscopy studies in Phase III.
The Precision Reactor Oscillation and SPECTrum (PROSPECT) experiment is a short-baseline reactor experiment with the goal of measuring the antineutrino spectrum from the High Flux Isotope Reactor (HFIR). It searches for potential short-baseline oscillations and the existence of sterile neutrinos. PROSPECT has already set new limits on the existence of eV-scale sterile neutrinos while achieving the highest signal-to-background ratio on any surface antineutrino detector. The collaboration has developed an upgraded detector design, PROSPECT-II, to increase the detector’s statistics and physics sensitivity. In this poster, I will describe the major design features of the PROSPECT-II detector, highlighting improved design elements concerning the first-generation PROSPECT-I detector and discuss how these improvements will add to the first-generation oscillation and spectrum results.
The Jiangmen Underground Neutrino Observatory (JUNO) is located 650 meters underground in southern China. The central detector of JUNO, featuring 20 kton of liquid scintillator and 78% photo-sensitive coverage, is designed to achieve an energy resolution better than 3% at 1 MeV. The physics goals of JUNO include determining the neutrino mass ordering and precisely measuring the neutrino oscillation parameters by studying reactor neutrinos, as well as exploring solar, atmospheric, terrestrial and supernova neutrinos, et al. This poster presents detection potential for the diffuse supernova neutrino background (DSNB) at JUNO using the inverse-beta-decay (IBD) detection channel. With latest DSNB signal predictions, more realistic background evaluation and efficiency optimization of pulse shape discrimination (PSD), and additional triple coincidence cut, JUNO can reach the significance of 3σ for 3 years of data taking, and achieve better than 5σ after 10 years for a reference DSNB model. In the pessimistic scenario of non-observation, JUNO would strongly improve the limits and exclude a significant region of the model parameter space.
JUNO (Jiangmen Underground Neutrino Observatory) is a 20.000-ton multipurpose underground liquid scintillator detector, which is designed to study the fundamental neutrino parameters. The central detector of JUNO will be filled with a liquid scintillator (LS) mixture, composed of LAB as solvent, 2.5 g/l PPO as fluor and 3 mg/l bis-MSB as wavelength shifter. Given the huge mass, the high transparency and attenuation length (> 20 m @ 430 nm), high light yield (~1500 p.e./MeV) and low radioactive impurities ($^{238}$U,$^{232}$Th <10$^{-15}$ g/g) are key parameters for the scintillator, and fundamental to achieve the experimental goals of JUNO. In order to reach the desired LS indexes, a dedicated sequence of 5 purification processes has been studied and implemented with large scale plants (nominal flow rate 7 m$^{3}$/h) at JUNO site.
Firstly, the raw LAB is filtered through Al$_2$O$_3$ powder to improve its optical properties. The second step is the distillation in partial vacuum, in order to remove heavy and high-boiling impurities and further enhance the transparency. The PPO and bis-MSB are washed and dissolved into the LAB by the Mixing Plant, according to the LS recipe, and sent to the underground laboratory for the last two steps. The water extraction aims to get rid of polar radioisotopes and ions, while the gas stripping process is effective in removing gaseous contaminants naturally dissolved into the LS.
The first joint commissioning campaign of all the plants has been recently concluded onsite, to prepare the 6-months filling phase of JUNO detector. Several measurements and tests are accomplished on purified LS samples, to check the performances and evaluate the purification efficiency of the plants. In this poster, all plants will be introduced and some preliminary results will be presented.
We derive quantum kinetic equations for mixing neutrinos including consistent forward scattering terms and collision integrals for coherent neutrino states. Our derivation is valid for arbitrary neutrino masses and kinematics, it includes the local coherence effects, and a comprehensive set of generalized Feynman rules for computing the coherent collision integrals. We discuss the importance of helicity coherence and particle-antiparticle coherence in the case of adiabatic background fields and in the case of an external magnetic field using field theoretical methods, that is, we do not need to rely on toy models or simplified numerical analyses. Our results can be used, for example, to model neutrino distributions accurately in hot and dense environments and to study the production and decay of heavy neutrinos in colliders.
The neutrino mass is one of the still-to-be-solved puzzles of particle physics. Measuring the neutrino mass is possible by performing precision spectroscopy of the tritium beta-decay spectrum at its endpoint. Until now, experiments following this approach use molecular tritium and are therefore limited by the broadening of the molecular final state distribution.
For future experiments aiming for sensitivities as low as the lower boundaries obtained by neutrino oscillation experiments (0.05 eV/c$^2$ in case of inverted ordering, or 0.009 eV/c$^2$ for normal ordering), atomic tritium sources are essential.
Research on atomic tritium sources is performed at the Johannes Gutenberg University (JGU) in Mainz in the context of the Project 8 experiment and at the Tritium Laboratory Karlsruhe (TLK) of the Karlsruhe Institute of Technology (KIT) in the context of the KATRIN++ program.
Currently, the focus of the JGU group is on developing and characterizing a high-flow atomic source using inactive hydrogen, whereas the focus of the TLK group is on running a source with tritium for the first time, which is on schedule for operation by the end of 2024.
Subsequently, in a joint venture, these lines of research will be merged to create the Karlsruhe Mainz Atomic Tritium experiment (KAMATE).
The poster will present the current developments for atomic sources at JGU and KIT, and how we combine them into a joint effort to realize an atomic tritium source for future neutrino mass experiments.
MicroBooNE is a Liquid Argon Time Projection Chamber, able to image neutrino interactions with excellent spatial and timing resolution, enabling the identification of complex final states resulting from neutrino-nucleus interactions. This poster will provide an overview of measurements for rare final states, such as $\Lambda$ and η production. These processes both provide unique sensitivities to the interplay between nucleon-level cross-section physics and nuclear-level physics, as well as account for sources of background in proton decay experiments. Furthermore, this poster showcases MicroBooNE’s measurements of total and first-order differential cross-sections on argon for muon neutrino interactions producing neutral pions in the final-state. These interactions will dominate the event rates observed at forthcoming high-precision neutrino experiments.
SNO+ is a neutrino detector located 2 km underground in SNOLAB, Canada,
whose main goal is to search for neutrinoless double-beta decay. In
addition, being about 240 to 350 km away from three large nuclear power
plants, it is well situated to measure neutrino oscillation parameter
Δm_21^2. Analyses of antineutrino signals, including the observation of
geoneutrinos in SNO+ (first measurement in the Western Hemisphere and in the North American plate), are underway. This poster presents an overview of the oscillation analysis being performed at SNO+, with projections for the sensitivities to Δm_21^2,theta_12, and the geoneutrino flux.
Neutrino experiments require high-speed data processing to extract valuable insights from large data sets. This poster presents an advanced real-time charge reconstruction algorithm for neutrino physics applications at the Jiangmen Underground Neutrino Observatory (JUNO), implemented on a field-programmable gate array (FPGA) platform.
The algorithm is designed to exploit the processing capabilities of the FPGA installed on the readout boards, ensuring real-time reconstruction of the charge based on the processing of the experiment’s Large Photomultipliers’ fully sampled waveform. By exploiting the flexibility and reconfigurability of FPGAs, the proposed solution achieves a balance between computational complexity and resource utilisation, making it well suited to address the demanding requirements of the JUNO experiment.
This poster outlines the key features of the algorithm, including its ability to handle high throughput data streams with low latency, its versatility and robustness in detecting the characteristics of the input data, and its performance evaluated on an actual JUNO electronics board.
It further demonstrates the potential of FPGA-based solutions to advance the field of neutrino physics. In particular, to detect transient astrophysical phenomena that would otherwise be lost.
In neutrino oscillation experiments, uncertainty in the reaction model between neutrinos and atomic nuclei in the low energy region of Sub-Multi GeV is one of the causes of systematic errors. The NINJA experiment aims to precisely measure the reaction between neutrinos and atomic nuclei in this low energy region.
The NINJA experiment measures neutrino reactions using a nuclear emulsion plate detector called an emulsion cloud chamber (ECC). ECC has submicron position resolution and can detect even low-momentum protons of 200 MeV/c.
The NINJA experiment involved irradiation (physical run) with J-PARC's high-intensity neutrino beam from November to February 2019, and analysis is currently underway.
In this presentation, we will report on the multiplicity of neutrino reactions and the momentum distribution of muons at the current stage.
The Short Baseline Near Detector (SBND), a 112-ton liquid argon time projection chamber (LArTPC), is the near detector of the Short Baseline Neutrino Program at Fermilab. Due to its large mass and proximity to the Booster Neutrino Beam target, SBND will see a record-breaking number of neutrino interactions on liquid argon enabling a rich program of neutrino cross-section measurements. Of particular interest are channels resulting in final states dominated by electromagnetic activity, such as charged-current electron neutrino interactions and neutral-current neutral pion production, due to their relevance in electron neutrino appearance searches. In addition to the unprecedented statistics and the excellent
imaging of LArTPCs, SBND is also equipped with a cosmic ray tagger and a state-of-the-art photon detection system, outfitted with 312 optical detectors. The intersection of SBND’s subsystems will not only provide precise, high-resolution measurements but will also support novel reconstruction techniques not previously achievable in LArTPCs, such as light calorimetry. This poster will give an overview of the current selections for the inclusive charged-current electron-neutrino and neutral-current neutral pion production channels, including the implementation of light calorimetric techniques and the use of all three SBND subsystems for cosmic rejection
The Cosmic Neutrino Background (CNB) encodes a wealth of information, but has not yet been observed directly. To determine the prospects of detection and to study its information content, we reconstruct the phase-space distribution of local relic neutrinos from the three-dimensional distribution of matter within 200 Mpc/h of the Milky Way. Our analysis relies on constrained realization cosmological simulations and forward modelling of the 2M++ galaxy catalogue. We find that the angular distribution of neutrinos is anti-correlated with the projected matter density, due to the capture and deflection of neutrinos by massive structures along the line of sight. Of relevance to tritium capture experiments, we find that the gravitational clustering effect of the large-scale structure on the local number density of neutrinos is more important than that of the Milky Way for neutrino masses less than 0.1 eV. Nevertheless, we predict that the density of relic neutrinos is close to the cosmic average, with a suppression or enhancement over the mean of (-0.3%, +7%, +27%) for masses of (0.01, 0.05, 0.1) eV. This implies no more than a marginal increase in the event rate for tritium capture experiments like PTOLEMY. We also predict that the CNB and CMB rest frames coincide for 0.01 eV neutrinos, but that neutrino velocities are significantly perturbed for masses larger than 0.05 eV. Regardless of mass, we find that the angle between the neutrino dipole and the ecliptic plane is small, implying a near-maximal annual modulation in the bulk velocity.
The Deep Underground Neutrino Experiment (DUNE) is the next generation neutrino experiment currently under construction. It consists of a broadband neutrino beam at Fermilab, a high precision near detector, and the largest liquid argon time projection chamber far detector ever designed at the Sanford Underground Research Facility (SURF).
The Region of Interest (ROI) filter is designed for DUNE’s online Data Acquisition (DAQ) system to address data rate constraints and enable low energy physics in the <10 MeV range. The filter employs zero suppression on the detector signal, and by tuning the readout window and threshold the data rates can be reduced by >90%. Performance of the ROI is analyzed in LArsoft on MARLEY generated low energy MC events propagated through the detector simulation. Notably, the optimized ROI filter enables a lower trigger threshold for readout at ~5-10 MeV, allowing DUNE to explore low-energy physics, specifically focusing on solar boron 8 neutrinos which are relevant in this energy range. This advancement enhances DUNE's scientific capabilities, opening avenues for detailed analyses of previously inaccessible low-energy neutrino interactions.
The control of nuclear effects is crucial to guarantee the success of future neutrino oscillation experiments (HyperK
and DUNE) in the search of CP violation in the leptonic sector. In particular, recently published semi-inclusive measurements are very sensitive to the details of nuclear modeling.
Among the various processes contributing to the cross section, two-particle--two-hole (2p2h) excitations induced by meson-exchange currents are particularly relevant and difficult to model.
Presently, this process is implemented in Monte Carlo generators on the basis of {\it inclusive} calculations. This procedure involves assumptions and approximations difficult to control. The correct approach to implement a 2p2h model event generators for the {\it semi-inclusive} reaction is through a microscopic calculation of these contributions, which was so far missing in the literature.
In this work we assess for the first time the impact of 2p2h excitations on the semi-inclusive neutrino scattering process $(\nu_l,lN)$, using a fully relativistic nuclear model calculation that precisely incorporates antisymmetrization. The calculation encompasses all contributions involving the exchange of a single pion and the excitation of a $\Delta$ resonance. Our results are coherent with previous inclusive electron scattering [1] and neutrino scattering [2] studies and are tested in the electromagnetic sector. Comparisons with $(e,e'p)$ data on carbon at kinematics where two-nucleon emission dominates are presented [3], as well as predictions for semi-inclusive neutrino scattering.
[1] A. De Pace, M. Nardi, W.M. Alberico, T.W. Donnelly, A. Molinari, The 2p - 2h electromagnetic response in the quasielastic peak and beyond, Nucl.Phys.A 726 (2003), 303-326
[2] I. Ruiz Simo, J. E. Amaro, M. B. Barbaro, A. De Pace, J. A. Caballero and T. W. Donnelly, Relativistic model of 2p-2h meson exchange currents in (anti)neutrino scattering,'
J. Phys. G \textbf{44} (2017) no.6, 065105
[3] V. Belocchi, M. B. Barbaro, A. De Pace and M. Martini,
Relativistic meson-exchange currents in semi-inclusive lepton scattering, submitted to PRL [arXiv:2401.13640 [nucl-th]]
Neutrino-neutrino dispersion models have gained popularity as potential solutions for reconciling the discrepancy between local measurements of the Hubble constant ($H_0$) and the model-dependent measurements derived from the cosmic microwave background radiation and other early Universe probes. This work addresses the current state of neutrino self-interactions, with a specific focus on the phenomenology associated with resonant interactions. We compare our results to existing limits on mediator mass, encompassing both extremely light and heavy scalar particles.
Recent advances in the development of cryogenic particle detectors, such as the magnetic microcalorimeter (MMC), allow the fabrication of sensor arrays with an increasing number of pixels, enabling measurements with unprecedented energy resolution. Since these detectors must be operated at the lowest temperatures, the readout of large detector arrays is still quite challenging due to strict limits regarding the number of signal lines interfacing the cryostat and the maximum readout power. This is especially true for the ECHo experiment, which aims to simultaneously run 6,000 two-pixel detectors to further narrow down the upper limit of the electron neutrino mass. The system has 400 two-pixel detectors connected to a common readout line via a microwave SQUID multiplexer ($\mu$MUX). For the operation of the cold electronics and to perform online data elaboration, we developed a room-temperature readout system using a software-defined radio (SDR) scheme.
The SDR readout electronics follow a modular approach with three distinct hardware units: a digital data processing board using a Xilinx ZynqUS+ MPSoC; a converter board featuring DACs and ADCs with a coherent clock distribution network; and a radio frequency front-end board to translate the signals between the baseband and the microwave domains. In this contribution, we present the overall system architecture as well as the individual stages of the data processing chain. Subsequently, we show the performance and characterization results of the full-scale SDR system. The generated frequency comb for driving the $\mu$MUX resonators was evaluated regarding signal-to-noise ratio (SNR) and spurious free dynamic range (SFDR). Additionally, the crosstalk and amplitude noise of each individual channel, after frequency demultiplexing, were investigated by operating the SDR in direct loopback mode. Overall, the performance of the full-scale SDR system showcased its capability to reliably read and process the massively parallel detector array data.
In the standard interaction framework, directly measuring absolute neutrino masses through neutrino oscillations isn't feasible since oscillations rely solely on mass-squared differences. However, the introduction of scalar non-standard interactions can incorporate additional terms in the oscillation Hamiltonian, directly impacting the neutrino mass matrix. This characteristic renders scalar NSI a unique tool for neutrino mass determinations. In this study, for the first time, we set constraints on the absolute masses of neutrinos by probing scalar NSI. We demonstrate that the presence of scalar NSI at DUNE can impose a bound on the lightest neutrino mass. We observe that the tightest constraint on the lightest neutrino mass occurs with $\eta_{\tau\tau}$ and $\eta_{\mu\mu}$ at $2\sigma$ confidence levels for normal and inverted hierarchy, respectively. This analysis suggests that scalar NSI presents an intriguing avenue for constraining absolute neutrino masses in long-baseline neutrino experiments through neutrino oscillations.
References:
[1] S.-F. Ge and S. J. Parke, Scalar Nonstandard Interactions in Neutrino Oscillation, Phys. Rev. Lett. 122 (2019) 211801 [1812.08376].
[2] A. Medhi, D. Dutta and M. M. Devi, Exploring the effects of scalar non standard interactions on the CP violation sensitivity at DUNE, JHEP 06 (2022) 129 [2111.12943].
[3] K. Babu, G. Chauhan and P. Bhupal Dev, Neutrino nonstandard interactions via light scalars in the Earth, Sun, supernovae, and the early Universe, Phys. Rev. D 101 (2020) 095029 [1912.13488].
[4] A. Medhi, M. M. Devi and D. Dutta, Imprints of scalar NSI on the CP-violation sensitivity using synergy among DUNE, T2HK and T2HKK, JHEP 01 (2023) 079 [2209.05287].
[5] DUNE collaboration, Deep Underground Neutrino Experiment (DUNE), Far Detector Technical Design Report, Volume IV Far Detector Single-phase Technology, JINST 15 (2020) T08010 [2002.03010].
[6] A. Medhi, A. Sarker and M. M. Devi, Scalar NSI: A unique tool for constraining absolute neutrino masses via $\nu$-oscillations, 2307.05348.
While primarily searching for neutrinoless double-beta decay in $^{130}$Te, CUORE demonstrates that bolometric detectors have reached sufficient size and scale to track through-going particles. Novel track-reconstruction tools and analysis techniques have been developed to study track-like events in the detector, including exotic signatures such as those induced by hypothetical fractionally-charged particles (FCPs) which arise from Beyond-the-Standard Model extensions. Experiments such as CUORE compliment collider-based and bulk matter searches for FCPs by looking for track-like signatures with suppressed energy deposition, on account of their reduced electric charge. We exploit the experiment's low-background environment to report on a search for an underground flux of fractionally charged particles with CUORE.
The ICARUS detector in the Short-Baseline Neutrino program at Fermilab is sensitive to “long-lived” new physics particles that would be produced in the Neutrinos at the Main Injector (NuMI) beam and decay inside the ICARUS liquid argon time projection chamber (LArTPC). We show results from a new analysis in ICARUS which searched for di-muon decays from a long-lived particle produced in kaon decay in the NuMI beam. The search is sensitive to new areas of parameter space for the Higgs portal scalar and an axion-like particle model. The sensitivity is also presented in a model-independent way applicable to any new physics model predicting the process K → π + S(→ μμ), for a long-lived particle S. This is the first search for new physics performed with the ICARUS detector at Fermilab. It paves the way for the future program of long-lived particle searches at ICARUS.
Lorentz invariance (LI) is a fundamental symmetry in physics that ensures that the same equations can be used to describe experiments in any inertial laboratory. Many proposed quantum gravity theories predict a violation of this symmetry, which is referred to as Lorentz invariance violation (LIV). The "Standard-Model extension" parametrizes physically valid ways of including LIV into the Standard Model of particle physics by introducing a set of LI- and CPT-violating operators coupled with coefficients. A non-zero value of at least one of these coefficients results in a deviation of the predicted neutrino oscillation probabilities from the case of standard neutrino oscillations, which enables neutrino telescopes to measure or constrain these coefficients. The ANTARES neutrino telescope, which was in operation from 2007 to 2022, and the KM3NeT/ORCA neutrino telescope, which is currently being built and already taking data, are two water-Cherenkov telescopes located in the Mediterranean deep sea. Both experiments are sensitive to the atmospheric neutrino flux, which has energies and baselines suitable for constraining LIV coefficients, with neutrino interactions being detectable by KM3NeT/ORCA6 at energies above a few GeV. This contribution reports on the progress of a combined analysis of data collected with ANTARES and with KM3NeT/ORCA6, an early-stage implementation of KM3NeT/ORCA with only six of the planned 115 detection units. The analysis focuses on isotropic LIV coefficients up to mass dimension six, among which some are still unconstrained.
Super-Kamiokande (SK) is known as the most sensitive detector to the supernova neutrinos originating in our galaxy.
SK also has a sensitivity to neutrinos from the extra-galactic supernova within 10 Mpc from Earth, called a “mini-burst”, which is expected to occur once every few years. Recently, SN2023ixf, one of the mini-bursts, is famous as the closest supernova in the last few years. Mini-bursts like SN2023ixf have been reported in worldwide telescopes in past decades. Therefore, we searched supernova neutrinos from the mini-burst from the time when SK started (1996) to the present (2024).
This poster shows the search results of the “mini-burst neutrino” search and their detection probability, including extra-galactic regions, in SK.
Grand Unified Theories explain the unification of the electromagnetic, weak, and strong forces and most of them predict protons to decay into lighter particles. The latest result of the proton decay search for $p\rightarrow e^+/\mu^+ +\eta$ channels in Super-Kamiokande will be discussed in this presentation. The cross sections of $\eta$ nuclear effect are improved compared to previous work, resulting in reducing their uncertainties by a factor of two. We analyze the data exposure of 0.373 Mton$\cdot$years (3244.4 live days) of Super-Kamiokande. No significant data excess was found above the expected number of atmospheric neutrino background events and no indication of proton decay was observed for either mode. The lower limits on the partial lifetimes of $1.4\times\mathrm{10^{34}~years}$ for $p\rightarrow e^+\eta$ and $7.3\times\mathrm{10^{33}~years}$ for $p\rightarrow \mu^+\eta$ were imposed at 90$\%$ CL, around 1.5 times longer limits than the previous study. These results set the most stringent limits in the world.
The XENONnT experiment has been built at the Laboratori Nazionali del Gran Sasso (LNGS) in order to continue the search for dark matter in the form of weakly interactive massive particles (WIMPs). Thanks to its low energy threshold and unprecedentedly low background level, the physics reach of XENONnT has expanded from the direct detection of WIMPs to a variety of rare event searches such as solar neutrinos, supernova neutrinos, axion-like particles, and second-order weak decays. For the latter, the two-neutrino electron capture with positron emission in the Xe-124 isotope is likely to be observed with the current generation of multi-tonne xenon experiments. This contribution will present an overview of the analysis strategy and the challenges of the search with the XENONnT detector.
Coherent Elastic Neutrino-Nucleus Scattering (CEvNS) is an interaction well predicted by the Standard Model. Its large cross-section allows to study neutrinos with relatively small detectors. Precision measurement of the CEvNS cross-section is a way to study neutrino properties and search for new physics beyond the Standard Model. The NUCLEUS experiment aims to detect and characterize CEvNS using reactor neutrinos, in an ultra-low background environment. The NUCLEUS target detector will be a 10g array of cubic CaWO4 and Al2O3 crystals with 5mm side. The experiment will be installed between two 4.25 GW reactor cores at the Chooz-B nuclear power plant in France. The experiment is currently under commissioning at the 15 m.w.e. underground lab at TUM (Munich) and will move to Chooz in 2024. The recent results and prospects of NUCLEUS will be presented.
Secondary mesons are produced in the stratosphere when primary cosmic rays collide with atmospheric molecules. Muons from secondary meson (mainly pions and kaons) decays can be detected in underground laboratories. As the temperature increases, the atmospheric density decreases, resulting in a reduced probability of meson interaction with atmosphere molecules and an increased probability of their decays, leading to an increase in the muon intensity. The same effects can be found for muon interaction and muon decays. In underground labs, only high energy muons will be detected. Thus, a positive correlation between muon intensity and atmospheric temperature are expected and the correlation coefficient is expected to change with the overburdens. The Daya Bay Reactor Neutrino Experiment, with three underground experimental halls at different depths, provides an ideal setup to perform such measurement. Positive correlation has been reported by many experiments. With full dataset of more than 14 billion muon events, a more precise measurement of the correlation coefficients is expected. This poster will present the current status of this measurement using full dataset from the Daya Bay Experiment.
The most successful method of probing neutrino mass directly is beta decay spectroscopy. The Project 8 experiment is pursuing a next-generation direct neutrino mass measurement with a target sensitivity of $40\rm{meV/c^2}$. To this end, the collaboration has developed the technique of Cyclotron Radiation Emission Spectroscopy (CRES), a frequency-based approach for measuring differential beta decay spectra. We employ an analytic model of neutrino mass uncertainty to predict the sensitivity of differential tritium decay measurements. Specifically, we implement features of CRES signal detection and systematic effects of a resonant cavity CRES experiment as is planned by the Project 8 collaboration. Based on this model, we optimize design parameters and discuss the experimental requirements for the final phase of Project 8. We also address the experimental needs for the upcoming phase, which seeks to achieve sub-eV sensitivity.
The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton multipurpose underground liquid scintillator (LS) detector currently under construction in southern China. One of the capabilities of JUNO detector is to search for the baryon number violation processes, which would be a crucial step towards testing the Grand Unified Theories and explaining the matter-antimatter asymmetry of the Universe. The nucleon decay provides a direct observation of baryon number violation and has been the focus of many experiments over the past several decades. The large LS detector of JUNO has a distinct advantage in detecting nucleon decay. The JUNO LS target consists of about 88% 12C and 12% 1H. The invisible decays of neutrons from the s-shell in 12C will result in a highly excited residual nucleus. It has been found that some de-excitation modes of the excited nucleus can produce time- and space-correlated triple signals. This poster reports the JUNO sensitivity to search for invisible decay modes of the neutron. Based on the Monte Carlo simulation, we comprehensively estimate all possible backgrounds, including from inverse beta decay events of the reactor antineutrino ̄νe, natural radioactivity, cosmogenic isotopes and neutral current interactions of atmospheric neutrinos. Pulse shape discrimination and multivariate analysis, two machine learning techniques, are employed to further suppress backgrounds. Then a sensitivity to neutron invisible decays on JUNO will be presented.
LiquidO is an innovative particle detection paradigm using opaque liquid
scintillators. The emitted light is confined near its creation point and captured by an array of wavelength-shifting fibers. This enables high-resolution imaging for particle identification down to the MeV scale, giving LiquidO the potential for various practical applications in particle physics.
After the successful development of two prototypes and with a third currently under construction, the next step is to build a 5 to 10-ton detector at an ultra-near site of the Chooz nuclear power plant in France, about 35 m from the reactor core. This is part of an Innovation program (EIC-Pathfinder project - AntiMatter-OTech) for monitoring nuclear reactor activity. The CLOUD collaboration, composed of 20 nstitutions over 11 countries, plans to execute the fundamental science programme in parallel to this project.
Constructing the detector at the ultra-near site poses challenges, as being at the surface implies a high cosmic background rate. It also imposes strict constraints on design elements such as materials and maximum building size. This poster presents the ongoing simulation effort aiming at guiding the detector design. The CLOUD collaboration is on the path to a full detector simulation, from external shielding to inner detector, using the Ratpac software developed by the SNO+ collaboration. This is a crucial step to understand the capabilities of a LiquidO-based detector operated at a nuclear power plant.
The Jiangmen Underground Neutrino Observatory (JUNO) experiment aims to precisely measure reactor anti-neutrinos via the Inverse Beta Decay (IBD): $\bar{\nu}_{e} + p \rightarrow e^{+} + n$. With a baseline of about 53 km from the closest nuclear power plants in southern China, the experiment is optimised to determine the neutrino mass ordering. The IBD occurs inside the 20 kton Liquid Scintillator (LS) detector, with events characterized by two energy deposition signals separated by a time interval of about 200 $\mu$s. One significant background is the $^{13}$C($\alpha,~n$)$^{16}$O reaction, where the $\alpha$ particle, originating from the radio-impurities, interacts with the $^{13}$C nuclei in the LS. To precisely measure reactor anti-neutrinos, it's crucial to evaluate the energy spectrum and rate of this background. In this presentation, we will introduce the first dedicated Monte Carlo simulation of the $^{13}$C($\alpha,~n$)$^{16}$O background in the JUNO LS. The Monte Carlo simulation encompasses an event generator that uses the open-source Geant4-based simulation package, SaG4n. This is incorporated within the JUNO simulation framework, which also comprises detector simulation, electronics and the data structure. We will present for the first time the energy spectra of the estimated ($\alpha,~n$) background from the $^{238}$U and $^{232}$Th chains and from $^{210}$Po in the JUNO LS.
Modeling of rare neutrino processes often relies on either simple approximations or expensive detector simulations. The former is often not sufficient for interactions with complex morphologies, while the latter is too time-intensive for phenomenological studies. We present SIREN (Sampling and Injection for Rare EveNts), a new tool for neutrino phenomenology and experimental searches alike that enables accurate interaction and detector geometry modeling without the overhead of detailed detector response simulations. SIREN handles the injection of rare process final states and the associated weighting calculations with the speed needed for phenomenological investigations and the detail necessary for dedicated experimental searches. The extensible design of SIREN allows it to support a wide range of experimental designs and beyond-the-Standard-Model neutrino interactions. Users need only specify the physical process, detector geometry, and initial neutrino flux under consideration before they can accurately simulate a model in their detector of choice. We demonstrate the capability of SIREN through two examples: (1) Standard Model $\nu_\mu$ deep inelastic scattering in IceCube, DUNE, and ATLAS; and (2) heavy neutral lepton interactions in MiniBooNE, MINERvA, CCM. A variety of detector geometry descriptions, interaction cross sections, and neutrino fluxes are also provided for users to get started with immediately.
The PandaX-4T experiment, employing a two-phase xenon time projection chamber, aims at exploring various physics phenomena, including detecting astrophysical neutrinos and searching for dark matter. It has set a significant constraint on solar B-8 neutrino flux using commissioning data, with an effective exposure of 0.48 tonne-year through neutrino-nucleus coherent scattering. Additionally, it places stringent limits on sub-GeV light dark matter interactions with shell electrons scatterings, with a 0.63 tonne-year exposure. This poster presents an overview of PandaX-4T, analysis methods, and findings on solar B-8 neutrino flux and light dark matter.
Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) poses an irreducible background for direct dark matter search experiments. In this work we discuss the scenario of low-threshold, high-exposure cryogenic solid state experiments optimized for the search of low-mass dark matter. We show that experiments with energy thresholds of $\mathcal{O}$(eV) and exposures of $\mathcal{O}$(tonne-years), using CaWO$_{4}$ or Al$_{2}$O$_{3}$ targets, have discovery potential for dark matter interaction cross sections below the conventional definition of the neutrino floor. Furthermore, in absence of any dark matter events, we treat solar neutrinos as the main signal of interest. We show that sensitivity to the flux of pp and $^{7}$Be neutrinos, as well as CNO neutrinos can be achieved.
We determine the solar neutrino fluxes from the global analysis of the most
up-to-date terrestrial and solar neutrino data including the final results of the three phases
of Borexino. The analysis are performed in the framework of three-neutrino mixing with
and without accounting for the solar luminosity constraint. We discuss the independence
of the results on the input from the Gallium experiments. The determined fluxes are then
compared with the predictions provided by the latest Standard Solar Models. We quantify
the dependence of the model comparison with the assumptions about the normalization
of the solar neutrino fluxes produced in the CNO-cycle as well as on the particular set of
fluxes employed for the model testing.
The ICARUS experiment, utilizing Liquid Argon Time Projection Chamber (LAr TPC) technology, has been installed at Fermilab in Chicago, Illinois, following its initial operation in Italy and subsequent refurbishment at CERN. ICARUS completed commissioning in June 2022. Currently, the experiment is in the phase of analyzing data from its two runs of physics data acquisition and gearing up for the third run. While its primary objective is to function as the far detector of the Short Baseline Neutrino program (SBN), seeking sterile neutrino signatures, ICARUS also offers diverse physics capabilities, including searches beyond the standard model and measurements of cross-sections. In addition to being exposed to the common Booster Neutrino (BNB) beamline, ICARUS also receives off-axis neutrinos from the Main Injector (NuMI) beam. Due to the off-axis angle between NuMI and ICARUS, coupled with contributions from both pion and kaon decays to neutrino fluxes, interactions of NuMI neutrinos within ICARUS can be detected over a range of several GeV in energy. These interactions present opportunities for crucial cross-section measurements and model tests within an energy range that overlaps both the SBN oscillation search and a portion of the DUNE spectrum. This poster presentation will delve into our efforts to conduct a muon-neutrino cross-section measurement, where the signal is defined by events with no pions produced in the final state of the interaction, along with some preliminary muon-neutrino inclusive measurements. Additionally, it will provide updates on the current status and future plans, including reconstruction, selection, and analysis procedures.
The Neutrino Elastic Scattering Observation with NaI(Tl) (NEON) experiment aims to observe coherent elastic neutrino-nucleus scattering (CEvNS) using reactor electron antineutrinos with a 16.5 kg NaI(Tl) detectors. A novel crystal encapsulation technique has enhanced light collection efficiency, resulting in a yield of 22 to 25 photoelectrons per keV of light. The detection facility of the NEON experiment is situated within the tendon gallery of the Hanbit Nuclear Power Plant Unit 6 in Yeonggwang, South Korea that is 23.7 meters away from the reactor core. Physics data taking started in April 2022 and stable operation since resulted in collections of 461 days reactor-on data and 144 days off data. A background level of 7 counts/day/kg/keV at 0.6 keV was observed. In this presentation, I will provide an overview of the NEON experiment, as well as the analysis status for the low-energy regime to CEvNS observation.
The COHERENT collaboration made the first measurement of coherent elastic neutrino-nucleus scattering (CEvNS) and did so by employing neutrinos produced by the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The uncertainty of the neutrino flux generated from the SNS is on the order of 10% making it one of COHERENT's most dominant systematic uncertainties. To address this issue, a heavy water (D2O) detector has been designed to measure the neutrino flux through the well-understood electron neutrino-deuterium interaction. The D2O detector is composed of two identical modules designed to detect Cherenkov photons generated inside the target tank with Module 1 containing D2O as the target and Module 2 initially containing H2O for comparison and background subtraction. We also aim to make a measurement of the cross-section of the charged-current interaction between the electron neutrino and oxygen, providing valuable insight for supernova detection in existing and future large water Cherenkov detectors. In this poster, we present the construction and commissioning updates for Module 2 along with some analysis progress on Module 1.
NOvA is a long-baseline accelerator neutrino experiment at Fermilab whose physics goals include precision neutrino oscillation as well as cross-section measurements. We present the status of the measurement of a muon neutrino charged-current cross section with zero mesons in the final state at the NOvA near detector. This measurement is being made with respect to the kinematics of the final state muon. The chosen interaction channel is especially sensitive to quasielastic and meson exchange current interactions and aims to provide experimental constraints for the development of models of neutrino interactions. It will also provide a handle for constraining cross section systematic uncertainties in oscillation analyses in current and future experiments. For particle identification, we use a convolutional neural network (CNN) trained on individual particles simulated in the NOvA near detector that allows us to select the desired signal while reducing the potential bias from neutrino interaction modeling. Charged pion background constraining is further improved via Michel electron tagging.
The Short Baseline Near Detector (SBND), a 112 ton liquid argon time projection chamber (LArTPC), is the near detector of the Short Baseline Neutrino Program at Fermilab. Neutrino events in SBND will produce both ionization electrons and scintillation light, which will be detected at the Anode Wire Planes Plane Assemblies (APAs) and the Photon Detection System (PDS), respectively. Wire-Cell is a standalone software package for TPC simulation, ionization signal processing, and 3D event reconstruction for LArTPC experiments, enabling high performance physics analyses. In this poster, we present the status of Wire-Cell development in the SBND experiment. Additionally we also introduce a Deep Neural Network (DNN) in LArTPC signal processing, to improve traditional signal Region of Interest (ROI) detection, and discuss the improvements over traditional ROI finding especially for certain track topologies using parameters such as bias and resolution of charge extraction
The Jiangmen Underground Neutrino Observatory (JUNO) is a critically important neutrino experiments aimed at determining the mass hierarchy (MH) of neutrinos. It is currently under construction and will be filled with 20k tons of liquid scintillator (LS) to mainly observe the reactor anti-neutrinos from two sets of nuclear reactors located 53 km away. In order to reach the goal of 3$\sigma$ sensitivity of MH measurement within 6 years of operation, the background control of the material used in the detector is stringent, which requires an extremely high purity of LS. The primary contributors to background in JUNO’s LS are radioactive isotopes, mostly from the decay chain of $^{238}$U/$^{232}$Th. The Online Scintillator Internal Radioactivity Investigation System (OSIRIS) is a pre-detector of JUNO dedicated to monitor the radioactivity contamination of LS prior to its introduction into the JUNO central detector. The OSIRIS detector is now filled with 18 tons of LS and 550 tons of pure water inside the cylindrical tank, which are monitored by 76 20-inch photomultiplier tubes. This poster will report the measurement on radioactivity purity of LS observed by OSIRIS, including the detection strategy and preliminary results based on the current dataset.
DUNE will exploit a wide-band neutrino beam and the energy spectrum information at the level of both the 1st and 2nd oscillations maxima in order to achieve its sensitivity to CP violation. This sensitivity is obtained by comparing the energy spectra of oscillated events with neutrinos and antineutrinos.
This work is investigating the neutrino energy reconstruction in DUNE starting from final state particles, and on how this is affected by the neutrino interactions physics/modelling. The potential interest aims at optimizing the energy resolution at low energy, corresponding to the second oscillation maximum, in order to further enhance the CP sensitivity.
Different event generators as GENIE and GiBUU are compared investigating several aspects, such as the interplay of different processes from quasi-elastic, resonances to deep inelastic scattering; nuclear effects and final state interactions.
Since SN1987A, we know that supernovae (SNs) produce burst of
neutrinos which can be detected several minutes to hours before the
electromagnetic burst. Detecting this neutrino burst would provide
valuable information on the supernova explosion mechanism and allow
to give an early warning of the imminent eletromagnetic burst arrival
to the astronomer community. The Super-Kamiokande experiment, with its
50 ktons water Cerenkov detector, is one of main neutrino detector
able to provide this warning. In this poster, we will present the last
status and improvements of the Super-Kamiokande's supernova monitoring
system.
COSINUS (Cryogenic Observatory for SIgnatures seen in Next-generation Underground Searches) is an underground cryogenic sodium iodide (NaI) experiment for the direction detection of dark matter. The experimental facility consists of a water Cherenkov muon veto surrounding the dilution refrigerator that holds NaI detector modules. Both the veto and the modules are sensitive to neutrinos given a sufficient flux, such as from a core-collapse supernova. The water tank main detection channel is inverse beta decay, while the cryogenic detectors are mainly sensitive to neutrinos through coherent elastic neutrino-nucleus scattering (CEvNS). The cryogenic detectors are sensitive to neutrinos from supernova that are hundreds of parsecs away, but are much less susceptible to pile-up from close supernova neutrinos compared to larger detectors. The water tank is sensitive to supernova that are tens of kiloparsecs away mainly due to the higher mass of the water compared to the mass of the NaI.
There have been considerable efforts to measure the parameters of the neutrino mixing matrix PMNS (Pontecorvo-Maki-Nakagawa-Sakata). The least known of these parameters is the complex CP-violating phase, $\delta_{\text{CP}}$. Accelerator experiments are the leading candidates to measure it with high significance. Supernova neutrinos, on the other hand, have never been considered to this date, due to their small energy, high uncertainty, and, most of all, lack of information about the full flavor components of the flux. This work is intended to address some of these issues and offer a complementary probe of such parameter.
We show how it is possible to extract some information about the PMNS matrix complex phase, $\delta_{\text{CP}}$, using supernova neutrinos. First, we use the next-to-leading order (NLO) calculation for the cross-section of neutrino-electron elastic scattering to distinguish between muon neutrinos and tau neutrinos at the detection. Consequently, one can use this flavor information to probe the CP-violating phase. We also explore the possibility of detecting high energy (100-200 MeV) neutrinos from shock acceleration which can also produce muons in the detector and provide a clear signal of flavor conversion that can also be used as a probe of $\delta_{\text{CP}}$.
Theia is a proposed large-scale neutrino detector that would use both scintillation and Cherenkov light to achieve the lower-energy threshold and finer energy resolution of scintillator detectors, coupled with the direction resolution and particle identification capabilities of water Cherenkov detectors. Such a “hybrid” detector could achieve an extremely broad physics program, including measurements of low energy solar neutrinos, geoneutrinos, supernova neutrinos, and neutrinoless double beta decay. Additionally, Theia would be able to measure $\delta_{CP}$ and the neutrino mass hierarchy if placed within the LBNF neutrino beam. An international community is pursuing the cutting edge technologies to realize this hybrid detector, including novel liquid scintillators that can be modified to adjust the scintillation yield and profile, fast photon detectors, and concentrators for chromatic photon sorting. Enhanced techniques for reconstructing particle energy, position, and direction, and characterizing events in hybrid detectors are also being developed and demonstrated, leveraging both AI/ML and traditional techniques. Several technology demonstrators are currently operating or under construction, which will demonstrate the performance of this technology, and its applicability to a rich program of physics. This poster will describe the program of R&D currently underway to demonstrate these advanced technologies and techniques.
Theia is a proposed large-scale neutrino detector designed to discriminate between Cherenkov and scintillation signals in order to enable a rich program of fundamental physics. The baseline design consists of a tank filled with a novel scintillator, such as water-based liquid scintillator (WbLS), along with fast, spectrally-sensitive photon detection, in order to leverage both the direction resolution of the Cherenkov signal and the remarkable energy resolution and low detection threshold of a scintillator detector. This poster will present the breadth of the Theia physics program, from low-energy neutrino physics, such as solar, geo, supernova burst, and diffuse supernova background neutrinos, as well as measurements of $\delta_{CP}$ and the neutrino mass ordering using high-energy neutrinos from the LBNF neutrino beam. Moreover, Theia can be adapted to search for neutrinoless double-beta decay, with a sensitivity reaching the normal ordering regime of neutrino mass phase space.
Coherent elastic neutrino nucleus scattering (CEvNS) was proposed 50 years ago within the standard model. The cross section of this process depends quadratically on the number of neutrons in nuclei and prevails over all other cross sections of known neutrino interactions in the allowed energy region, below approximately 50 MeV for heavy nuclei. At the same time, the recoil energy for this process is very small and difficult to detect. Thus, it was observed only in 2017 by the COHERENT experiment for the first time on the CsI target at Spallation Neutron Source (SNS) located in Oak Ridge National Laboratory (USA). The primary program of COHERENT is to detect CEvNS on different targets to study its cross section dependence on the number of neutrons in nuclei which can reveal deviations from the standard model and can be a probe for the nonstandard neutrino interactions. In addition to the first observation the COHERENT already succeeded in detecting this process on Ar and Ge targets with the latter very recently in 2023.
In this poster, we describe the current status of the CEvNS study in the COHERENT experiment as well as our efforts to measure inelastic neutrino interactions with O, Ar, I, Pb, and Th nuclei. We update our program for neutrino flux measurements at SNS with heavy water detectors. Also, we present other COHERENT efforts and possible reach at the Second Target Station of SNS.
The CONUS+ experiment is a new project which aims to detect coherent elastic neutrino-nucleus scattering (CEνNS) of reactor antineutrinos on germanium nuclei in the fully coherent regime, continuing in this way the CONUS physics program. The CEνNS signature will possibly be measured with the four 1 kg point-contact high-purity germanium (HPGe) detectors of the former experiment, which have been refurbished, further improving their energy thresholds. The CONUS+ experiment was installed during summer 2023 in the Leibstadt nuclear power plant, Switzerland, at a distance of about 20 m from the 3.6 GWth reactor core. The experiment is fully operational since end of 2023 and it is currently in the physics data taking phase.
The CONUS+ design will be shown, together with the background characterization of the new experimental location and the commissioning phase of the experiment at reactor place. Finally, the physics potential of the project will be presented.
The ENUBET (Enhanced NeUtrino BEams from kaon Tagging) project is aimed at designing and experimentally demonstrating the concept of monitored neutrino beams. These novel beams are enhanced by an instrumented decay tunnel, whose detectors reconstruct large-angle charged leptons produced in the tunnel and give a direct estimate of the neutrino flux at the source. The detector technology for the instrumented decay tunnel was investigated by the ENUBET collaboration with an extensive prototyping activity which culminated in the construction of a Demonstrator (a prototype of the instrumented decay tunnel). The Demonstrator is a 1.7 m long quarter section of the instrumented tunnel which consists of a modular sampling calorimeter and a separate photon veto, allowing for an identification of the charged leptons at a single particle level. The goal of the Demonstrator is to show that with cost-effective technologies, it is possible to achieve charged leptons identification performance allowing for a reduction to ~1% of the overall uncertainty in the electron neutrino flux estimation. In this poster I will focus on the Demonstrator design and present preliminary analysis of the performance during the tests performed with charged particle beams at CERN East Experimental Area.
Photomultiplier tubes (PMT) are widely deployed at neutrino experiments for photon counting. When multiple photons hit a PMT consecutively, their photo-electron (PE) pulses pile up to hinder the precise measurements of the count and timings. We introduce Fast Stochastic Matching Pursuit (FSMP) to analyze the PMT signal waveforms into individual PEs with the strategy of reversible-jump Markov-chain Monte Carlo. We demonstrate that FSMP improves the energy and time resolution of PMT-based neutrino experiments, gains acceleration on GPUs and is extensible to microchannel-plate (MCP) PMTs with jumbo-charge outputs. In the condition of our laboratory characterization of 8-inch MCP-PMTs, FSMP improves the energy resolution by up to 12% from the long-serving method of waveform integration.
Measuring the absolute mass of neutrinos remains a significant challenge in particle physics and astrophysics. The only theory-unrelated method to assess its value is through direct measurements, which involve a kinematic analysis of electrons emitted in beta decays. The experiments aiming to perform such a measurement fall into two categories: spectrometers and calorimeters. Spectrometers like KATRIN set stringent limits, yet face limitations due to the fact that the source is external to the detectors with possibility of systematics. Calorimeters, on the other hand, embed sources within low-temperature detectors, measuring the entire energy released by the decay except the fraction carried by the neutrino. Balancing statistical sensitivity and unresolved pile-up fraction, crucial for calorimeters, involves distributing the total activity across numerous detectors, necessitating multiplexing readout.
HOLMES is an experiment seeking to assess the feasibility of measuring the neutrino mass with a sub-eV sensitivity by measuring the electron capture of 163Ho calorimetrically. The nuclei of 163Ho are embedded in the detectors with a custom ion-implanter. The detectors are readout using the microwave multiplexing technique developed by NIST, which is based on the use of rf-SQUIDs as input devices with ramp modulation. The modulated signals are readout by coupling the rf-SQUIDs to superconducting lambda/4 resonators: by tuning resonators at different frequencies it is possible to achieve a large multiplexing factor, while providing a relatively large bandwidth per channel.
HOLMES has completed a thorough optimization of the detectors and multiplexing, achieving results that meet the requirement of the experiment. Following an extensive commissioning and testing phase, the custom ion implanter has been able to perform implantations at low dose (around 1 Hz) successfully. This milestone has represented a major progress for HOLMES, from which will plan to increase the specific activity in the detectors, to assess the contribution to the TESs total heat capacity due to the concentration of 163Ho.
In this contribution the collaboration presents the initial results following the first high-statistics data tacking campaign, discussing the status and the overall outlook of the experiment.
Over 50 years ago, it was predicted that it is possible to split an atom with a neutrino interaction, but there has never been a concerted experimental effort to confirm this phenomenon. The existence of this process would inform nuclear astrophysics, nuclear reactor monitoring and give a vantage into a process that bridges both the weak and strong fundamental interactions. This would add the neutrino to the selective group of particles confirmed to induce nuclear fission. To that end, the NuThor Detector was built in 2022 as a dedicated neutrino-induced nuclear fission (hereafter referred to as "nuFission") detector on thorium. The NuThor Detector hermetically seals 52.0 kgs of thorium metal inside a novel, custom-made neutron multiplicity meter built to efficiently capture and detect fission neutrons peeled off of the fissioned thorium nuclei. Said neutron multiplicity meter is composed of gadolinium-doped water to moderate and capture the aforementioned neutrons. Then an array of 7.7 kg NaI[Tl] scintillator crystals from the Homeland Security Advanced Portal Program are affixed all around the complex of thorium and Gd-Water to detect neutron-capture gamma rays. This entire apparatus is exposed to the intense neutrino flux of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The intense, pulsed neutrino source coupled with the NuThor apparatus presents a unique and promising opportunity to conclusively put this half century mystery of nuFission to rest.
The Mobile Antineutrino Demonstrator project aims to construct a realistically deployable antineutrino detection system that can operate at essentially any reactor facility with no infrastructure support beyond electrical power. Through engagement with potential end-users and host facilities, this effort will advance the technical readiness of neutrino-based reactor monitoring concepts by enabling operationally relevant demonstrations. The project is motivated by recent technology development that enables antineutrino detectors to operate at the earth’s surface and the results of the Nu Tools study which provided new insight into the utility of antineutrino measurements for current and foreseen nuclear security challenges. In this poster we will describe the mobile system design, selected antineutrino detector technologies, and measurement plans for the mobile system.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-861439
Coherent elastic neutrino nucleus scattering (CEvNS) off atomic nuclei was predicted in 1974, but only in 2017 it was experimentally observed by the COHERENT collaboration. RED-100 is a two-phase detector designed and built to study CEvNS of reactor antineutrinos. In 2022, the detector completed exposure at Kalinin Nuclear Power Plant with xenon as target material. Data collection included both reactor ON and OFF periods. In this poster, the final results of the experiment with Xe are presented. Various methods of data processing and analysis, including neural networks for background mitigation, are discussed. At the present moment, preparations for the new experiment with argon as target material are underway. Future plans and results of engineering tests and simulations are shown and discussed.
The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is a gadolinium-doped water Cherenkov neutrino detector located along the Booster Neutrino Beam (BNB) at the Fermi National Accelerator Laboratory (FNAL). Its primary physics goals are the measurement of the neutrino-nucleus interaction cross section in water, and the measurement of final-state neutron multiplicity from these interactions. Identifying neutrons is crucial for understanding uncertainties in energy reconstruction for oscillation measurements, as well as for the reduction of atmospheric neutrino backgrounds in searches for diffuse supernova neutrinos and proton decay. ANNIE is also used as a testbed for up-and-coming technologies for neutrino detectors. This poster will highlight the recent results of neutrino beam data analysis and examine the future potential of the ANNIE detector.
The LiquidO technology proposes a new paradigm of detection that uses an
opaque medium to confine light and wavelength-shifting fibers to collect it near
its point of emission. After a summary of the demonstration of light confinement
using a 10-liter prototype, we will explore a future project that will exploit this
technology.
The SuperChooz project is a neutrino oscillation experiment consisting of a
10 kton detector planned to be based near the Chooz nuclear reactor in France.
In the context of this project, we will explore the background rejection capabilities
of a LiquidO-based detector.
The main point of interest of the LiquidO technology is the possibility to
access the topology of an event. Therefore, we will mainly focus on the use of
spatial coincidences in neutrino reactions to reject background events. Through
the use of Monte-Carlo simulations, we will be testing different levels of spatial
resolutions. We will observe how those resolutions affect the background
rejection capabilities of the SuperChooz detector.
We will focus more closely on the reaction of neutrinos on $^115$In proposed
by Raghavan in 1976 to probe the solar neutrino spectrum.
A core-collapse Supernova in our own galaxy would be close enough to be seen with neutrinos in many of the world's neutrino and dark matter detectors. Those neutrinos exit the star promptly, while the electromagnetic fireworks appear ~hours later after the explosion's shock reaches the star's surface. An automated alert network allows a coincidence between detectors to be issued automatically, taking advantage of that early warning to get observations going at the earliest possible time: facilitating the extraction of the most data possible of this once or twice a century event. While SNEWS has been ready to do this for two decades, Multi-Messenger Astronomy has come a long way in that time, so SNEWS2.0 is being deployed with new infrastructure and the ability to do more than just a simple coincidence: public sub-threshold alerts; pointing to the supernova using inter-experiment triangulation; and searches for pre-supernova neutrinos. We will outline the capabilities and design of SNEWS 2.0, as well as its role in multi-messenger follow-ups.
While the unitarity of the neutrino mixing matrix is postulated in the standard three-flavour paradigm, it can be verified experimentally through neutrino oscillation measurements. In this study, we combine recent public data from the atmospheric and reactor neutrino experiments — including IceCube-DeepCore, Daya Bay, and KamLAND — and place model-independent constraints on the individual elements of the PMNS mixing matrix. To quantify non-unitarity, we compute the credible intervals for the normalizations of the matrix rows and columns and the closures of the unitarity triangles, highlighting the role of the atmospheric neutrino systematic uncertainties in our results. Finally, we report the sensitivity projections for the non-unitarity constraints that will be possible with the next generation of atmospheric and reactor neutrino experiments, focusing on IceCube-Upgrade and JUNO as direct successors to the experiments analyzed in this work.
The Jiangmen Underground Neutrino Observatory (JUNO) is a large-scale liquid scintillator detector constructed for neutrino detection. The detector will be situated in a laboratory ~700 meters underground to reduce the impact of cosmic muon-induced background. The central detector consists of a 20 kton liquid scintillator target enclosed within an acrylic sphere, surrounded by 17,612 20-inch large Photomultiplier Tubes (PMTs). Additionally, a 34 kton ultrapure water pool encompasses the central detector, with 2400 20-inch PMTs installed to function as a Water Cherenkov detector for cosmic muon detection and background reduction. A top tracker detector for muon tracking is positioned above the water pool. The inner surface of the water pool's wall and the outer surface of the stainless lattice steel are coated with Tyvek reflectors to enhance light collection efficiency. A water purification and circulation system maintains high water quality, ensuring optimal detector performance. Furthermore, a 32-coil system serves as a geomagnetic shield to protect the PMTs inside the detector from the influence of the geomagnetic field. The cosmic muon detection efficiency of the Water Cherenkov detector exceeds 99%, and the cosmic muon-induced fast neutron background can be controlled to ~0.1 per day. This poster will provide an overview of the design and current status of the Water Cherenkov detector of JUNO.
SNO+ is a multi-purpose neutrino detector located 2 km underground at SNOLAB, Canada. The experiment is in operation with 780 tonnes of liquid scintillator as its target mass. The high light yield, low background levels, and planned long-term operation make SNO+ suitable for precision measurements of high energy solar neutrinos (E > 5 MeV) and provide the opportunity to detect low energy solar neutrinos. Exploring the time profile of the scintillator light allows to access a wide range of information about the events in the detector, providing powerful tools to discriminate between backgrounds and solar neutrino signals. This poster will present the time-based event discrimination methods under development by the SNO+ collaboration, including event-by-event directionality that has recently been published. These methods are being optimized to maximize signal-to-background for solar neutrino (and for all) analyses.
The Jiangmen Underground Neutrino Observatory (JUNO) is a multipurpose observatory currently under construction in China. JUNO's physics reach will span many areas, amongst which precision neutrino oscillation measurements using reactor neutrinos, solar, atmospheric and geoneutrino related measurements.
In order to reduce the backgrounds from the atmospheric neutrino flux, the JUNO detector is located 650 m underground. Even at this depth, decays from cosmogenic isotopes miming the inverse beta decay (IBD) signature, used to identify electron antineutrinos, are expected to appear about as often as the IBDs themselves. To remove this background a dedicated cut around muon tracks passing through the detector is required. The JUNO veto system, composed of the Top Tracker (TT) and of the Water Cherenkov Detector (WCD), was designed with the goal of tracking those muons to make it possible to directly measure their flux and use it in the aforementioned veto strategy to suppress the cosmogenic background contamination.
The TT is made using refurbished plastic scintillator modules of the Target Tracker of OPERA equiped with new electronics. It will cover about 60% of the surface above the WCD. This makes it possible for the TT to precisely track about a third of the muons crossing the detector with a median resolution of about 0.2$^\circ$. While the TT won't be able to track all muons of interest, it will produce a sample of well tracked muons to calibrate the other subdetectors of JUNO and help tune their reconstructions.
This poster will discuss the current status of the JUNO Top Tracker, covering in particular updates made since its usage in OPERA and its performance in JUNO.
The extremely weak interaction of neutrinos makes them both challenging to study and excellent cosmological messengers as they can escape the most dense astrophysical objects. As a result, neutrinos can play a crucial role in answering some of the most important questions at both the smallest and largest scales of the universe. The next generation of accelerator-produced high-energy neutrino experiments, like the Deep Underground Neutrino Experiment (DUNE), will be sensitive to astrophysical neutrinos, providing a wealth of unique information about particle physics, as well as astrophysical objects.
However, many astrophysical neutrinos arrive with energies of a few tens of MeV – much lower than the typical accelerator energies. Very little is known about the interaction of these low-energy neutrinos and this key information is needed to fully interpret their measurements. The Short Baseline Near Detector (SBND) neutrino experiment plans to measure the probability of interaction of similar low-energy neutrinos coming from muons-decay-at-rest (𝜇DAR), an intrinsic side product of the neutrino beam. In this poster, the progress towards detecting muon decaying at rest electron neutrinos is shown, focusing on the trigger requirements and light detection and timing capabilities of SBND.
The detection of neutrinos from the next galactic Core Collapse Supernova (CCSN) is a unique opportunity to study its explosion mechanism with profound implications in astrophysics, nuclear physics, and particle physics. The Jiangmen Underground Neutrino Observatory (JUNO), currently under construction in Southern China, is a 20-kiloton liquid scintillator detector equipped with two independent sub-systems: 17612 20-inch PMTs and 25600 3-inch PMTs. With its large volume, unprecedented energy resolution, and the sensitivity to all neutrino flavors, JUNO is competitive for low energy astrophysical neutrino studies, such as the CCSN. Initially designed as a calibration system for non-linearity effects of the 20-inch PMTs, the 3-inch PMT system can provide complementary results especially in the case of exceptionally high-rate events and saturated signals. This poster presents the capabilities of the 3-inch PMTs in detecting the next CCSN. It highlights the detector response, especially under the extraordinary circumstance of a nearby CCSN, and showcases the performance in neutrino identification.
Thanks to their excellent energy resolution, cryogenic microcalorimeters are a particularly suitable detector choice for calorimetric neutrino mass experiments, where the ability of precisely resolving decay spectra is essential. Transition Edge Sensors (TESs) and Magnetic Microcalorimeters (MMCs) are employed in the HOLMES and ECHo experiments, respectively. In order to increase the sensitivity of these experiments, the number of microcalorimeter pixels needs to be scaled up, requiring a multiplexed read-out approach. Typically, this is implemented via a Microwave SQUID Multiplexing (μMUX) approach, coupling each microcalorimeter pixel to a superconducting microwave resonator, respectively. These resonators are coupled to one common transmission line and their responses are monitored via a frequency domain multiplexing technique, which allows for a reconstruction of the events in each single detector pixel. In state-of-the-art μMUX set-ups, the read-out noise is ultimately limited by the HEMT amplifier stage. Such limitation inevitably compromises the detectors’ intrinsic energy resolution of about
1.5 eV, worsening it up to 10 eV. This limitation can be overcome by introducing a (quasi) quantum limited microwave amplifier between the μMUX and the HEMT, featuring high gain (≥ 20 dB), large bandwidth (several GHz), and high saturation power (≥ -50 dBm). In this contribution, we present the development of superconducting parametric amplifiers, such as Travelling Wave Parametric Amplifiers (TWPAs) based on high kinetic inductance NbTiN artificial transmission lines. This work has been performed in the framework of the DARTWARS project (2020-2024), funded by INFN and MSCA, and it will continue within the MiSS project (2024-2027), funded by Horizon Europe. The design, microfabrication and cryogenic characterisation of these parametric amplifiers are discussed and the most recent results are presented, paving the way towards quantum limited read-out of cryogenic microcalorimeter detectors for neutrino mass experiments.
The Karlsruhe Tritium Neutrino (KATRIN) experiment aims to probe the effective electron anti-neutrino mass by measuring the beta-decay spectrum of molecular tritium close to the endpoint region. By the end of 2025, a final sensitivity better than $0.3\,\mathrm{eV}/c^2$ ($90\,\%$ CL) will be anticipated with a total of 1000 days of measurement. For going beyond, i.e. to set up a next-generation neutrino mass experiment probing inverted or even normal mass ordering, novel, ground-breaking technology must be developed to significantly improve statistics, energy resolution and background reduction. One potential strategy is the upgrade / extension of the present KATRIN beamline by an atomic tritium source as well as an energy-dispersive quantum sensor to measure the energy of the electrons passing the main KATRIN spectrometer operated with a fixed retarding potential. To judge the suitability of such an approach, we initiated the ELECTRON project aiming to proof that magnetic microcalorimeters (MMCs), a special type of superconducting quantum sensor, can be employed for high-resolution electron spectroscopy without performance degradation and to investigate potential systematic effects occurring for electron detection. Outside of ELECTRON, we also study how MMCs can be made resilient to magnetic background fields in the range of 10-$100\,\mathrm{mT}$ and how quantum sensor arrays can be coupled to a warm beamline without using radiation windows. In this contribution, we will present the present status our work as well as very recent measurements yielding a $^{83m}$Kr spectrum with the present best energy resolution. We will also discuss our efforts put towards the first ever measurements of the tritium $\beta$-decay spectrum using a novel compact tritium source. Finally, we will outline some ideas how to operate a superconducting quantum sensor array at the KATRIN beamline.
The upgrade of the T2K magnetised near detector (ND280) is near completion in J-PARC. After detecting the first neutrinos in Fall 2023, ND280 is collecting new data in 2024 with a beam intensity above 700 kW. The new active target, the Super Fine-Grained Detector (SFGD) is made up of about 2 million 1 $\textrm{cm}^3$ scintillation cubes, thereby offering excellent timing resolution and isotropic tracking.
In this work, we present the preliminary Transverse Kinematic Imbalance (TKI) reconstruction with and without pion at the T2K near detector upgrade. The Elastically Scattered Contained protons technique is used to select a high-quality proton sample for $\nu_\mu CC0\pi^+ 1p$ TKI analysis. The reconstruction shows promising resolution. The pion trackless reconstruction exploits the unique time signal of its decay chain to reconstruct the primary pion in a neutrino nucleus interaction without requiring the presence of a reconstructed track. Hence, it transcends the tracking threshold and further lower the pion reconstruction limit. Additionally, the reconstruction quality of the trackless technique is also excellent. Moreover, a $\nu_\mu CC 1\pi^+1p$ selection, based on the trackless technique and, has been produced for a preliminary study of the TKI variables. Furthermore, owing to the excellent resolution of the hadronic kinematic variables, a new set of variables, the Centre-of-Momentum (COM) variables, are devised and serve as excellent Final State Interactions (FSI) probes independent of the initial nucleon state. As the COM variables are sensitive to FSI differently from the TKI variables, it shows potential results that the two are used together to select a Hydrogen sample with high purity.
The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment currently under construction in southern China.
The detector consists of a 35.4 m diameter acrylic sphere filled with 20 000 t of ultra-pure liquid scintillator and makes JUNO the largest liquid scintillator-based, underground neutrino observatory. The primary goal of JUNO is to determine the neutrino mass ordering with a significance greater than 3$\sigma$ after 6 years of data taking and to perform high-precision measurement of neutrino oscillation parameters by measuring the spectrum of the oscillated reactor antineutrino. The detector construction is expected to be completed in 2024.
JUNO has extremely stringent requirements for its background that can overlap with the signals of interest. One of the main background sources is the decay of radioactive nuclides in the materials of the detector and a big effort is necessary to keep the radioactive contamination under control by selecting and purifying the materials used to build the experiment. The most critical component is the liquid scintillator (LS) which is the active material of the detector: the baseline requirements for its radiopurity are less than $10^{-15}$ g/g for $^{238}$U and $^{232}$Th and less than $10^{-16}$ g/g for $^{40}$K.
To achieve the required sensitivities, a new measurement technique has been developed to increase the typical sensitivity of the Neutron Activation Analysis (NAA). We’ve combined the NAA with radiochemical treatments on the sample to concentrate the nuclides of interest and remove the interfering ones, a new delayed coincidence technique for the measurement of $^{238}$U by exploiting the presence of a metastable state in the Uranium activation product, and a dedicated $\beta-\gamma$ coincidence detector to suppress the measurement background. We achieved sensitivities of <0.7 ppq for U, < 8.2 ppq for Th and <1.7 ppq for K and validated the first samples of JUNO LS produced during the commissioning of the purification plants.
The choice of unfolding method for a cross-section measurement is tightly coupled to the model dependence of the efficiency correction and the overall impact of cross-section modeling uncertainties in the analysis. A key issue is the dimensionality used, as the kinematics of all outgoing particles in an event typically affects the reconstruction performance in a neutrino detector. OmniFold is an unfolding method that iteratively reweights a simulated dataset using machine learning to utilize arbitrarily high-dimensional information that has previously been applied to collider and cosmology datasets. Here, we demonstrate its use for neutrino physics using a public T2K near detector simulated dataset, and show its performance is comparable to or better than traditional approaches using a series of mock data sets.
The Karlsruhe Tritium Neutrino (KATRIN) Experiment directly measures the neutrino mass-scale with a target sensitivity of 0.3 eV/c^2 by determining the shape change in the beta spectrum near the endpoint. The Rear Wall is used to maintain a homogenous starting potential distribution over the full magnetic flux tube volume in the gaseous tritium source. During operation, tritium is circulated from the gaseous source and through the beamline. In this process, small amounts of tritium adsorb on the Rear Wall. Because the Rear Wall tritium has different conditions such as temperature than those of the gaseous source tritium, the Rear Wall tritium has a different spectrum than that of the gaseous source tritium. This Rear Wall tritium spectrum is superimposed onto the spectrum from the gaseous source, and thus is treated as a background. Not accounting for this background tritium spectrum from the adsorbed tritium results in a potential bias in the extraction of the neutrino mass. In this poster, we will discuss this background tritium spectrum, the efforts being made to understand it, and the size of its systematic contribution to KATRIN’s neutrino mass results.
The neutrino has a lifetime that is significantly longer than the Age of the Universe, as it can only decay radiatively via loops involving gauge bosons. However, the presence of physics Beyond the Standard Model could induce 'visible' neutrino decay between neutrino mass eigenstates. This decay process could be identified in laboratory experiments as well as from astrophysical or cosmological observations. To study neutrino systems that involve both oscillation and decay, two main formalisms have been developed---a density matrix approach and a phenomenological approach. In this work, we present an analysis of both, highlighting the physical effects captured by each framework.
The Large Volume Detector (LVD) at the INFN Gran Sasso National Laboratory, Italy, whose main goal is the detection of neutrino bursts from core-collapse supernovae in the Galaxy, has been taking data since 1992. The updated search for neutrino bursts, including the most recent data up to 2024, is presented. The analysis yielded no evidence of neutrino bursts, imposing a new upper limit to the rate of core-collapse supernovae in the Galaxy.
SNO+ is a large liquid scintillator-based experiment located 2km underground at SNOLAB, Sudbury, Canada. It reuses the Sudbury Neutrino Observatory detector, consisting of a 12 m diameter acrylic vessel filled with about 780 tonnes of ultra-pure liquid scintillator. The high overburden and cleanliness procedures give low background rates. Combined with the kiloton scale experiment, it is possible to measure Boron-8 solar neutrinos. Different approaches for detecting Boron-8 solar neutrinos in liquid scintillators are being explored and will be presented.
KM3NeT/ORCA is a 7 Mton water-Cherenkov neutrino detector being built by the KM3NeT Collaboration at the bottom of the Mediterranean Sea at a depth of 2450 meters off the coast of Toulon, France.
The main goal of this experiment is to determine the neutrino mass ordering as well as measuring oscillation parameters for the atmospheric neutrino sector.
The ORCA detector has been growing in size with more detection units being deployed every year.
The first analysis of a new data sample including detector configurations with 6, 10 and 11 detection units will be presented in this contribution.
The sample corresponds to a 3 year period from January 2020 to December 2022.
The newest measurement of the mixing angle $\theta_{23}$ and the mass splitting $\Delta m^2_{31}$ using atmospheric neutrinos will be discussed. Additionally, the sensitivity of the ORCA detector to the neutrino mass ordering using the current available data will be reported.
In recent years, neutron multiplicity associated with neutrino-nucleus interactions has become important observable in large neutrino detectors such as Super-Kamiokande, KamLAND, and JUNO. The neutron multiplicity can be measured by detecting gamma rays emitted by neutron capture by taking delayed coincidence. It is expected to improve the results of various physics analyses by using the measured neutron multiplicity to enhance flavor identification or signal-to-background ratio. However, predicting neutron multiplicity is challenging because neutrino-nucleus interactions involve highly uncertain nuclear effects.
Among the several processes involved in neutrino-nucleus interactions, nuclear deexcitation plays an important role in neutron multiplicity. This process emits particles, including neutrons, while transitioning to the ground state when the residual nucleus has exciting energy after the nucleon is knocked out. One issue is that most widely used neutrino interaction generators omit this process or describe it with a simplified model. Another issue is that the energy of deexcited particles is as low as a few MeV and, therefore, unobservable, i.e., un-constrainable, by most accelerator neutrino detectors due to higher detection thresholds. This feature of deexcitation requires us to rely on precise nuclear theory and experiments to verify it.
The author developed a dedicated nuclear deexcitation simulator, NucDeEx, based on the nuclear calculation software TALYS. Since TALYS contains sophisticated nuclear models and parameters, NucDeEx can precisely simulate the nuclear deexcitation process. In addition, NucDeEx can be easily integrated with the neutrino interaction generators and other hadron simulators, such as Geant4 and the hadron cascade model INCL. The source code of NucDeEx and the interfaces and build scripts necessary for use with the above software are available on the web. Thus, a wide range of applications are expected. In this poster, the author will present an overview of NucDeEx, validations with nuclear experiments, the impact of integrating NucDeEx into neutrino interaction generators, and its application to other particle simulators.
Paper: Phys. Rev. D 109, 036009
NucDeEx GitHub: https://github.com/SeishoAbe/NucDeEx
Hot white dwarfs lose energy mainly in the form of neutrinos through plasmon decay from the inner part of the star. BSM physics can have visible contributions to the cooling of these compact objects. The aim of this study is to show how hot white dwarf cooling could be altered by a dark photon from the L_mu - L_tau model and explore these effects from ultra-light to heavy intermediators. This leads to very interesting constraints to this BSM model.
The method of indirect detection of dark matter (DM) particles in neutrino telescopes involves the observation of Cherenkov signals left by their annihilation or decay products. An excess of neutrinos produced by these processes is searched in nearby astrophysical targets such as the Galactic Centre or the Sun, where large amounts of DM are believed to accumulate. The KM3NeT infrastructure, located in abyssal sites of the Mediterranean Sea, is composed of two undersea Cherenkov neutrino telescopes: ORCA, a dense detector optimised for the measurement of low energy neutrinos, and ARCA, a cubic kilometer detector, intended for low fluxes of of astrophysical neutrinos. The energy range covered by ORCA allows the study of weakly interacting massive particles (WIMPs) in the 1-100 GeV/c$^2$ mass range and ARCA allows to study 500 GeV/c$^2$ to 100 TeV/c$^2$ DM masses; the analysis is extended to lower masses with respect to other water-based neutrino experiments such as ANTARES and IceCube. In this contribution we present an analysis with an unbinned likelihood method looking for WIMP-like DM annihilations occurring at the Galactic Centre using a partial detector configuration with 6 lines (ORCA-6). Results obtained for higher masses with a partial ARCA configurations (ARCA-6/8/19/21) are also discussed.
The SBND (Short Baseline Near Detector) is the near detector of the short baseline neutrino program (SBN) at Fermilab. SBND, is located at 110 m from the neutrino beam and will collect an impressive statistic of neutrino-argon interactions. SBND will also serve as a test bed for new technologies for LAr-TPCs. In particular SBND implements different and complementary solutions for the detection of LAr scintillation light. LAr light is emitted in a narrow 10 nm band centered around 127 nm, in the Vacuum Ultra-Violet and the shape of the signal is the sum of two exponential decays with very different characteristic time constants (6 ns and 1,500 ns). Scintillation light can be used to perform calorimetric measurements of the deposited energy, event-time determination of the neutrino interaction and particle discrimination through pulse shape studies.
The Photon Detection System is a combination of traditional, large area (8") photomultipliers and X-ARAPUCAs using SiPMs, a novel detector which is the baseline choice of the Deep Underground Neutrino Experiment.
The PDS will collect not only the direct VUV LAr light, but also a component in the visible range, shifted by the layer of Tetra-Phenyl Butadiene (TPB – emission wavelength around 430 nm) deposited on reflective foils installed on the cathode of the TPC. This will allow us to test a new version of X-ARAPUCA which is sensitive to visible light, and SBND is the only experiment which will operate this version of X-ARAPUCA.
Though liquid argon time projection chambers (LArTPCs) excel at reconstructing neutrino interactions at ~100s of MeV in energy, their physics reach can be enhanced by extending reconstruction to much lower energies. MicroBooNE has demonstrated reconstruction capabilities for energy depositions at the ~MeV and sub-MeV scale, which manifest as isolated "blips" spanning only a few readout channels on the TPC wire planes. Using data from special R&D runs where MicroBooNE's LAr was doped with radon, new software tools were used to identify the beta and alpha decay products of progeny isotopes bismuth-214 and polonium-214. Measuring the rate of these correlated decays under different filtration configurations revealed that liquid-phase electronegative filters effectively mitigate radon contamination. Further studies using novel background subtraction techniques produced calorimetric energy spectra of these decay products, showcasing sensitivity down to ~100 keV in electron-equivalent energy for charge-based readout. These tools were then applied to standard data-taking conditions to set a radiopurity limit for ambient bismuth-214, the first of its kind for a large single-phase liquid-filtered LArTPC.
The Standard Model’s (SM) limitation in explaining neutrino masses and flavor mixing leads to an exploration of frameworks beyond the standard model (BSM). The study of neutrino properties, including oscillations and interactions, can provide clues for improving our overall understanding of nature. Neutrino oscillations, the transition between different neutrino flavors during long-distance propagation, serve as a key phenomenon for probing new physics. The possibility of neutrinos interacting with fermions via a scalar mediator is one of the most interesting prospects. These interactions have the potential to modify the standard neutrino oscillation probabilities, potentially manifesting observable effects in experiments. One of the most interesting aspects of scalar NSI is the exploration of the absolute masses of neutrinos via neutrino oscillation experiments, which is not possible through oscillation studies. Scalar non-standard interactions (SNSIs) of neutrinos offer a compelling avenue to potentially reveal physics beyond the SM. The study of SNSI via neutrino oscillation experiments can help constrain the properties of scalar mediators.
In this work, we have focused on the influence of off-diagonal scalar NSI elements on neutrino oscillation probabilities, particularly emphasizing the long baseline neutrino experiment, i.e., Deep Underground Neutrino Experiment (DUNE). Our analysis extends beyond individual elements to explore the intricate correlations and interplay between diagonal and off-diagonal scalar NSI components. We also explore its impact on the CP-Violation sensitivities at DUNE, as it may be significantly affected due to the presence of new CP phases. By delving into the complex interplay between different types of SNSI, this work will shed light on the CP-measurement sensitivities. This exploration of scalar NSI effects can provide valuable insights into the landscape of neutrino oscillations and CP violations.
Chair: John Learned
Light detection plays a central role in many current and planned neutrino experiments. This field has seen the flowering of many new ideas in the last few years, thanks to the development of new photo-sensors and new detection techniques, based on the use of advanced materials. This talk will review the most innovative and promising approaches to photon detection in neutrino physics in the last years with an eye on future applications.
Chair: Chiara Brofferio and Gioacchino Ranucci