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The Neutrino Telescopes Workshop dates back to 1988 when Prof. Milla Baldo Ceolin conceived it and launched the first edition.
The 2021 edition will focus to the original, at the time pioneering, topics of the workshop: Large Detectors for Neutrino Astrophysics, Neutrino Physics and Cosmology.
Due to Covid19 - Sars-Cov-2 circumstances, it will be held online. Registration is free but mandatory
Abstract submission for contributed talks and flash talks is now open. Conference proceedings will be published under the Zenodo platform.
The XIX International Workshop on Neutrino Telescopes is organized by INFN Sezione di Padova and by the Physics and Astronomy Department of Padova University.
Under the patronage of
University of Padova celebrating in 2022 its 800 years of activity
Sponsored by
Several anomalies had been collected for two decades in the neutrino sector beyond an ordinary 3-flavour mixing picture, suggesting the existence of some additional new related states.
Liquid argon TPC (LAr-TPC) is an ideal detection technology for neutrino physics, combining excellent 3D spatial reconstruction and calorimetry. The ICARUS-T600 detector has been he first large scale detector of this typology and its operation with the CNGS neutrino beam proven the maturity of the technique, while providing important results.
After a significant overhauling at CERN, the T600 detector has now been placed in its experimental hall at Fermilab where installation activities are in progress. It will be soon exposed to clarify in a definitive way the open questions of the presently observed neutrino anomalies. The contribution will address ICARUS achievements and plans for the sterile neutrino search at Fermilab. Data taking will begin during 2021.
FASERnu is a new experiment to measure interaction cross-sections of neutrinos that are produced in proton-proton collisions at the LHC. The detector will be installed 480 m downstream from the interaction point of the ATLAS experiment during 2021, aiming to collect physics data during Run 3 of the LHC. About 10,000 charged-current neutrino interactions with mean energies of ~1 TeV are expected in FASERnu. There are no existing neutrino cross-section measurements in this energy range. In addition, the measurement will reduce systematic errors on the forward charm production rate and constrain the prompt atmospheric neutrino background for the extragalactic neutrino searches at IceCube. FASERnu can detect interactions of all three neutrino flavors with the excellent track reconstruction capability, utilizing the emulsion detector in cooperation with the silicon tracking in FASER behind it. In this talk, the physics prospects for FASERnu as well as status of the detector construction and installation will be presented.
Neutrino interactions with nuclei are the main experimental tool used to study neutrinos in many different contexts, and systematic uncertainties arising from neutrino-nucleus interactions, especially those related to nuclear effects, can be a limiting factor in their energy reconstruction. For the CC1pi interaction, which is dominated by resonant production, physics of the initial state nucleon correlations, self-energy corrections of the force mediator, and the Delta resonance propagation inside the nucleus are not well-modelled. We present the first experimental study of nuclear medium effects in CC1pi+ interaction by measuring the kinematic imbalance between the muon, pion and proton in the plane transverse to the incoming neutrino. The extracted cross-section as a function of the imbalance is sensitive to the nuclear physics model and final state interactions. This new measurement provides unique constraints to characterize the nuclear effects in neutrino interaction modelling.
The detection of neutrinos through Coherent Elastic Neutrino Nucleus Scattering (CE$\nu$NS) process opens a new window to study the fundamental properties of this elusive particle and to probe physics beyond the Standard Model. The CONUS experiment – operational since April 2018 – is located at 17$\,$m from the 3.9$\,$GW$_{\text{th}}$ core of the nuclear power plant Brokdorf (Germany) and aims to detect CE$\nu$NS in the fully coherent regime with four 1 kg-sized HPGe point-contact detectors with a ~$\,$300$\,$eV$_{\text{ee}}$ energy threshold. The full spectral analysis of the first CONUS dataset including 248.7$\,$kg.d reactor-on and 58.8$\,$kg.d reactor-off allowed to set the current best limit on the coherent elastic scattering of reactor antineutrinos. This result will be presented, along with the details of the systematic uncertainties and the full Monte-Carlo description of the background. A special emphasis will be put on the strategy followed by the collaboration to further reduce the uncertainties, in particular via a dedicated measurement of the ionization quenching factor of nuclear recoils in germanium.
Hadron production measurements are crucial for helping long-baseline
neutrino oscillation experiments constrain their beam flux
uncertainties. These uncertainties represent a leading systematic
uncertainty on measured neutrino oscillation parameters. At the
NA61/SHINE experiment, interactions of charged hadrons with various
materials relevant to neutrino production are recorded and analyzed.
NA61/SHINE data has been used to significantly improve the
(anti)neutrino flux prediction at the T2K experiment. This talk will
present recent analysis results of 60 GeV/c and 120 GeV/c protons on a
carbon target, interactions relevant to neutrino production at DUNE.
More thin and replica target measurements are forseen at NA61/SHINE
after CERN's Long Shutdown 2.
The eV-scale sterile neutrino has been proposed to explain some anomalous results in experiments,such as the deficit of reactor neutrino fluxes and the excess of $\bar{\nu}_\mu\to\bar{\nu}_e$ in LSND. This hypothesis can be tested by future core-collapse supernova neutrino detection independently since the active-sterile mixing scheme affects the flavor conversion of neutrinos inside the supernova.
In this work, we compute the predicted supernova neutrino events in future detectors -- DUNE, Hyper-K, and JUNO -- for neutrinos emitted during the neutronization burst phase when the luminosity of $\nu_e$ dominates the other flavors.
We find that for a supernova occurring within 10 kpc, the difference in the event numbers with and without sterile neutrinos allows to exclude the sterile neutrino hypothesis at more than $99\%$ confidence level robustly.
The derived constraints on sterile neutrinos mixing parameters are comparably better than the results from cosmology and on-going or proposed reactor experiments by more than two orders of magnitude in the $\sin^22\theta_{14}$-$\Delta m_{41}^2$ plane.
Core-collapse supernovae are among the most magnificent events in the observable universe. They produce many of the chemical elements necessary for life to exist and their remnants—neutron stars and black holes—are interesting astrophysical objects in their own right. However, despite millennia of observations and almost a century of astrophysical study, the explosion mechanism of core-collapse supernovae is not yet well understood.
Hyper-Kamiokande is a next-generation neutrino detector that will be able to observe the neutrino flux from the next galactic core-collapse supernova in unprecedented detail.
We focus on the first 500 ms of the neutrino burst, corresponding to the accretion phase, and use a newly-developed, high-precision supernova event generator to simulate Hyper-Kamiokande’s response to five different supernova models. We show that Hyper-Kamiokande will be able to distinguish between these models with high accuracy for a supernova at a distance of up to 100 kpc.
Once the next galactic supernova happens, this ability will be a powerful tool for guiding simulations towards a precise reproduction of the explosion mechanism observed in nature.
The XENONnT detector recently started its commissioning phase at Laboratori Nazionali del Gran Sasso. Utilizing 5.9 tonnes of liquid xenon (LXe) as active target and designed for a high level of background reduction, it will greatly improve the results of its predecessor, XENON1T. Although primarily a dark matter (DM) detector whose main channel is the direct detection of Weakly Interacting Massive Particles (WIMPs), other channels such as the neutrinoless double beta decay of $^{136}$Xe, the two-neutrino double electron capture process in $^{124}$Xe, the standing excess of electronic recoil events observed in XENON1T data or the observation of coherent elastic scattering of $^8$B neutrinos in LXe will play a important role in XENONnT future analysis. Furthermore, XENONnT will also focus on multi-messenger astrophysics, acting as an active observatory of supernova neutrinos and contributing to the Supernova Early Warning System (SNEWS).
We report on the latest results of XENON1T and look into the planned future of XENONnT, highlighting its plans to look for supernovae events up to the Large Magellanic Cloud in real-time and connect with SNEWS, its inter-experiment coincidence trigger and triangulation mechanisms.
The “solar metallicity problem” is one of the most long-standing puzzles in solar physics. It consists in the discrepancy between several Sun physical properties predicted by solar models using updated metal abundances from spectroscopy (low-metallicity scenario, LZ-SSM), and those inferred from helioseismology, which favours a higher metal content (high-metallicity scenario, HZ-SSM). The solar neutrino fluxes depend on the chemical composition of the Sun: their precise measurements can be used to test the solar models, and to discriminate the between the two scenarios. A considerable progress in solar neutrino physics comes by the Borexino experiment, which recently claimed the first detection of neutrinos emitted from the CNO cycle. In this sequence, the hydrogen fusion is catalysed by carbon, nitrogen and oxygen, and so the flux of CNO neutrinos depends directly on the abundance of these elements in the solar core. For this reason, the CNO neutrinos flux strongly depend on the metallicity scenario, leading to a ~30% difference between the HZ-SSM and LZ-SSM predictions. In this talk, the implications of the CNO detection by Borexino for solar physics are discussed, combining this latest result with the previous measurement of 7Be and 8B neutrino fluxes. In this way, a mild preference for HZ scenario is found, disfavouring LZ hypothesis at a level of 2.1σ significance. Moreover, the impact of future experimental improvements for the CNO neutrino flux determination will be addressed. This work is presented on behalf of the Borexino Collaboration.
The latest data of the two long-baseline accelerator experiments NO$\nu$A and T2K, interpreted in the standard 3-flavor scenario, display a tension. A mismatch in the determination of the standard CP-phase $\delta_{\mathrm {CP}}$ extracted by the two experiments is evident in the normal neutrino mass ordering. While NO$\nu$A prefers values close to $\delta_{\mathrm {CP}} \sim 0.8 \pi$, T2K identifies values of $\delta_{\mathrm {CP}} \sim 1.4 \pi$. Such two estimates are in disagreement at more than 90$\%$ C.L. for 2 degrees of freedom. In this talk, we show that such a discrepancy can be resolved if one hypothesizes the existence of complex neutral-current non-standard interactions (NSI) of the flavor changing type involving the $e-\mu$ or the $e-\tau$ sectors with couplings $|\varepsilon_{e\mu}| \sim |\varepsilon_{e\tau}|\sim 0.2$. Remarkably, in the presence of such NSI, both experiments point towards the same common value of the standard CP-phase $\delta_{\mathrm {CP}} \sim 3\pi/2$. Our analysis also highlights an intriguing preference for maximal CP-violation in the non-standard sector with the NSI CP-phases having best fit close to $\phi_{e\mu} \sim \phi_{e\tau}\sim 3\pi/2$, hence pointing towards imaginary NSI couplings.
We study the phenomenology of the minimal (2,2) inverse-seesaw model supplemented with Abelian flavour symmetries. To ensure maximal predictability, we establish the most restrictive flavour patterns which can be realised by those symmetries. This setup requires adding an extra scalar doublet and two complex scalar singlets to the Standard Model, paving the way to implement spontaneous CP violation. It is shown that such CP-violating effects can be successfully communicated to the lepton sector through couplings of the scalar singlets to the new sterile fermions. The Majorana and Dirac CP phases turn out to be related, and the active-sterile neutrino mixing is determined by the active neutrino masses, mixing angles and CP phases. We investigate the constraints imposed on the model by the current experimental limits on lepton flavour-violating decays, especially those on the branching ratio BR(μ→eγ) and the capture rate CR(μ−e,Au). The prospects to further test the framework put forward in this work are also discussed in view of the projected sensitivities of future experimental searches sensitive to the presence of heavy sterile neutrinos. Namely, we investigate at which extent upcoming searches for μ→eγ, μ→3e and μ−e conversion in nuclei will be able to test our model, and how complementary will future high-energy collider and beam-dump experiments be in that task.
The phenomenon of Neutrino Oscillation has been very well confirmed by a plethora of data; we are now entering a precision era in which the mixing angles and mass differences are going to be measured with unprecedented precision by ongoing and planned experiments. However, the new measurements could reveal that the standard three flavor scenario is not enough for a complete description of oscillations and a new paradigm beyond the standard physics in the lepton sector must be invoked. In this talk I will review the current experimental situation on neutrino masses and mixing and discuss some example of physics beyond the Standard Model that could show up in the next years.
Ultra High Energy neutrinos may represent a unique opportunity
to unveil possible new physics interactions in the neutrino sector. At
this regard, we have investigated the effects on high and ultrahigh energy
active neutrino fluxes due to active-sterile secret interactions mediated
by a new pseudoscalar particle. These interactions become relevant at
very different energy scales depending on the masses of the scalar
mediator and of sterile neutrino. As a consequence, we have found
interesting phenomenological implications on two benchmark fluxes we
consider, namely an astrophysical power law flux, in the range below 100
PeV, and a cosmogenic flux, in the Ultrahigh energy range. These features could be measurable in present and future neutrino experiments.
The goal of the presented analysis is the measurement of the muon antineutrino single $\pi^{-}$ production interactions on CH ($\bar\nu_{\mu} + N \rightarrow \mu^{+} + \pi^{-} + X$) in the T2K off-axis near detector. This interaction mode is the second largest at T2K energies and studies are ongoing to include such events in T2K oscillation analysis which for $\bar\nu_{\mu}$ beam mode is currently limited to Charged Current (CC) quasi-elastic events. For this reason, a more detailed understanding of this interaction channel using near detector data is becoming increasingly vital. The measurement will be a double differential cross-section in muon kinematics and will be extracted using a binned likelihood fit. The event selection strategy developed for this analysis along with the validation studies performed to check the analysis robustness are discussed in this presentation.
Electron-neutrino appearance is a crucial channel for searches of sterile neutrinos in short-baseline experiments and measurements of Charge-Parity (CP) violation in long-baseline oscillation experiments. The precise knowledge of the electron neutrino cross section will, therefore, play a key role in reducing the uncertainties of these future experiments. There are only a handful of electron neutrino cross section measurements in the hundred MeV to GeV range and only one on argon. Therefore, there is a need for new, high statistics measurements of this quantity. MicroBooNE is a Liquid Argon Time Projection Chamber (LArTPC) located at Fermilab which simultaneously receives a flux of neutrinos from the on-axis Booster Neutrino Beam (BNB) beam and off-axis Neutrinos at the Main Injector (NuMI) beam. While MicroBooNE uses BNB data for short baseline sterile oscillation searches, data from the NuMI beam provide an excellent opportunity to simultaneously measure the electron-neutrino cross section, thanks to its higher electron-neutrino flux component. This talk will cover the current status of inclusive charged-current electron neutrino cross-section measurement on argon in MicroBooNE using the NuMI beam.
Neutrino interactions off correlated nucleon pairs (2p2h interactions) are thought to contribute significantly to events detected by long baseline neutrino oscillation experiments. These 2p2h processes are challenging to model and the corresponding uncertainties can be responsible for some of the leading systematic uncertainties in measurements of neutrino oscillation parameters. To help alleviate these uncertainties in future measurements, T2K aims to precisely characterise 2p2h interactions at it's near detector facility (ND280). A key signature for 2p2h interactions is the production of final states with multiple nucleons. However, ND280 is only able to reconstruct protons and only those above 450 MeV/c momenta. The consequence of this high momentum threshold is that the majority of 2p2h interactions are thought to leave at least one proton below detection threshold. To circumvent this issue, recent analysis efforts have tried to tag low momentum protons via calorimetric measurements of energy deposited near the neutrino interaction vertex, so called "vertex activity". This talk presents such an analysis considering events with one reconstructed muon track, one reconstructed proton track and a search for a 2nd proton in the vertex activity.
The MicroBooNE detector has an active mass of 85 tons of liquid argon and is located along the Booster Neutrino Beam (BNB) at Fermilab. It has a rich physics program including the search for a low-energy excess observed at MiniBooNE and measurements of neutrino-Argon interaction cross sections. In this talk, we present a procedure, based on the Wiener-SVD unfolding method, to extract the nominal neutrino flux-averaged total and differential cross sections of the inclusive muon neutrino charged-current interaction on argon. This procedure relies on a minimal set of assumptions while maximizing the power in comparing data results with predictions from theory and event generators. Taking advantage of the power of a Liquid Argon Time Projection Chamber (LArTPC) and the Wire-Cell tomographic event reconstruction paradigm, this procedure enables a new round of cross section measurements at MicroBooNE.
Recently the first direct observation of CNO neutrinos was achieved with a high statistical significance. This challending observation was made using the highly radiopure liquid-scintillator detector Borexino located in the Laboratori Nazionali del Gran Sasso in Italy. The spectral shape of CNO neutrino interactions in the liquid scintillator of the Borexino detector is very similar to that of the main background: intrinsic 210Bi decays. The ensuing high correlations in Borexino's spectral fits make an independent determination of a 210Bi constraint necessary in order to claim a measurement or discovery of CNO neutrinos. In this talk the methods used to extract the 210Bi rate from 210Po data, selected with pulse shape discrimination methods, are discussed, as well as how systematic uncertainties were treated.
Borexino is an experiment designed and constructed for real-time detection of low energy solar neutrinos. It is installed at the underground Laboratori Nazionali del Gran Sasso (L’Aquila, Italy) and started taking data in May 2007. Today, the detector is characterized by an extreme and unique radiopurity. The Borexino collaboration has recently published the first direct measurement of the CNO (Carbon-Nitrogen-Oxygen) solar neutrinos rate: this measurement is crucial for the precision modeling of solar physics and for astrophysics in general.
In this contribution, I present the event selection criteria and the strategy adopted by the Borexino collaboration for successfully isolating the spectral component of the CNO signal from the residual backgrounds: a multivariate analysis performed by simultaneously fitting the energy and radial distributions of selected events.
Solar neutrino experiments have had great success in furthering our understanding of the neutrino sector and the Sun. Experiments like BOREXINO, KamLAND, and SuperKamiokande are also sensitive to antineutrino fluxes at the level of sub per-mille of the B8 neutrino flux. We explore this in our work to derive constraints on a model of decaying sterile neutrinos, recently proposed as a solution to the LSND, MiniBooNE anomalies.
Observation of Supernovae through their neutrino emission is a major fundamental point to understand both supernovae dynamics and neutrino physical properties. JUNO is a multi- purpose neutrino experiment with a 20 kton liquid scintillator detector under construction in Jiangmen, China. The main aim of the experiment is to determine neutrino mass hierarchy by precisely measuring the energy spectrum of reactor electron antineutrinos at a distance of ∼ 53 km from the reactors. For the next galactic core-collapse supernova (SN),JUNO has the capability of detecting a high statistics of SN events. While existing data from SN neutrino consist only of a few events coming from the SN1987A, the detection of a SN burst in JUNO from a progenitor star at 10 kpc will yield ∼ 5 × 103 IBD events from electron antineutrinos, around 2000 events from all flavor elastic neutrino-proton scattering, as well as more than 300 events from neutrino-electron scattering, and the charge current and neutral current interaction of neutrinos on the 12C nuclei. In this work an study of SN neutrino events with the JUNO detector through their main three channels is presented with the aim of reconstructing the neutrino energy spectrum separately and all together. The reconstruction of the supernova neutrino energy spectra is based on a probabilistic unfolding method.
The Jiangmen Underground Neutrino Observatory (JUNO) will play an essential role in detecting neutrinos from core-collapse supernova (CCSN). Designed with a 20 kt liquid scintillator detector, JUNO has capability to register all flavors of O(10MeV) supernova burst neutrinos with several channels. Even the O(1 MeV) pre-supernova neutrinos from the advanced stages of stellar evolution are detectable for the nearby progenitors, thanks to the low energy threshold of the liquid scintillator detector. For the next CCSN in the Galaxy and its vicinity, a real-time monitor system with supernova burst neutrinos and pre-supernova neutrinos as diagnostics is currently under development in JUNO, to provide early alerts for its multi-messenger follow-up observations. Besides, JUNO's sensitivity to the neutrino flux from all the supernovae occurred in the Universe in aggregate (Diffuse Supernova Neutrino Background, DSNB) is competitive to that of the Super-K with gadolinium phase, and will be discussed as well.
We explore the evolution of a select grid of solar metallicity stellar models from their pre-main sequence phase to near their final fates in a neutrino Hertzsprung-Russell diagram, where the neutrino luminosity replaces the traditional photon luminosity. Using a calibrated MESA solar model for the solar neutrino luminosity ($L_{\nu,\odot}$ = 0.02398 $\cdot$ $L_{\gamma,\odot}$ = 9.1795 $\times$ 10$^{31}$ erg s$^{-1}$) as a normalization, we identify $\simeq$0.3 MeV electron neutrino emission from helium burning during the helium flash (peak $L_{\nu} / L_{\nu,\odot} \simeq$ 10$^4$, flux $\Phi_{\nu, {\rm He \ flash}} \simeq$ 170 (10 pc/$d$)$^{2}$ cm$^{-2}$ s$^{-1}$ for a star located at a distance of $d$ parsec, timescale $\simeq$ 3 days) and the thermal pulse (peak $L_{\nu} / L_{\nu,\odot} \simeq$ 10$^9$, flux $\Phi_{\nu, {\rm TP}} \simeq$ 1.7$\times$10$^7$ (10 pc/$d$)$^{2}$ cm$^{-2}$ s$^{-1}$, timescale $\simeq$ {0.1 yr) phases of evolution in low mass stars as potential probes for stellar neutrino astronomy. We also delineate the contribution of neutrinos from nuclear reactions and thermal processes to the total neutrino loss along the stellar tracks in a neutrino Hertzsprung-Russell diagram.
We find, broadly but with exceptions, that neutrinos from nuclear reactions dominate whenever hydrogen and helium burn, and that neutrinos from thermal processes dominate otherwise.
Neutrinos have played a key role in astrophysics, from the characterization of nuclear fusion processes in the Sun to the observation of supernova SN1987A and multiple extragalactic events. The Super-Kamiokande experiment has played a major part in past in these astrophysical studies by investigating low energy O(10)MeV neutrinos and currently exhibits the best sensitivity to the diffuse neutrino background from distant supernovae. Discovering and characterizing this signal however presents significant challenges due to important backgrounds from cosmic muon spallation and atmospheric neutrinos. Reducing these backgrounds will require implementing state-of-the-art neutron tagging algorithms to discriminate between different types of interactions, as well as a thorough characterization of spallation-inducing mechanisms. Here, I present an overview of the search for the DSNB in Super-Kamiokande, and discuss how the current strategies will evolve after the SuperK-Gd upgrade.
We all know that in the dense anisotropic interior of the star, neutrino- neutrino forward-scattering can lead to fast collective neutrino oscillations, which has striking consequences on flavor dependent neutrino emission and can be crucial for the evolution of a supernova and its neutrino signal. Although the triggering and initial growth of fast oscillations are understood, owing to its complicated nonlinear evolution, the final impact is not yet known. Interestingly, stellar explosion and the neutrino signal are sensitive to the processed flavor-dependent fluxes, but the required neutrino theory prediction is still lacking. In my talk I will address this crucial theoretical and phenomenological obstacle and present a theory of fast flavor conversions that will explain how, when and to what extent do the flavor differences change. Finally, I will give a method and a simple formula for computing the final fluxes that can be a crucial input for supernova theory and neutrino phenomenology. This work solves a critical problem revealing the fi?nal state of fast conversions that has eluded the community for almost two decades with two fundamentally new physical insights, viz., coarse-grained evolution and transverse relaxation.
https://mediaspace.unipd.it/media/XIX+International+Workshop+on+Neutrino+Telescopes+- +Parallel+Room+2/1_1vlcxx4w?st=8850&ed=9040
Neutrino oscillations occur due to non-zero masses and they are believed to maintain quantum coherence even over astrophysical length scales.It is thus natural to explore geometric aspects of the phases involved as well as think about quantification of the coherence properties of neutrinos via temporal correlations in the form of Leggett-Garg Inequalities (LGI). In this paper, we study the quantumness of three flavor neutrino oscillations by studying the extent of violation of LGI if non-standard interactions are taken into account. We report an enhancement in violation of LGI with respect to the standard scenario for certain choice of NSI parameters.
We calculate the rates of radiative $\beta^- \to \alpha^- + \gamma$ decays for $(\alpha, \beta) = (e, \mu)$, $(e, \tau)$ and $(\mu, \tau)$ by taking the {\it unitary} gauge in the $(3+n)$ active-sterile neutrino mixing scheme, and make it clear that constraints on the unitarity of the $3\times 3$ Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix $U$ extracted from $\beta^- \to \alpha^- + \gamma$ decays in the {\it minimal unitarity violation} scheme differ from those obtained in the canonical seesaw mechanism with $n$ heavy Majorana neutrinos by a factor $5/3$. In such a natural seesaw case we show that the rates of $\beta^- \to \alpha^- + \gamma$ can be used to cleanly and strongly constrain the effective apex of a unitarity polygon, and compare its geometry with the geometry of its three sub-triangles formed by two vectors $U^{}_{\alpha i} U^*_{\beta i}$ and $U^{}_{\alpha j} U^*_{\beta j}$ (for $i \neq j$) in the complex plane. We find that the areas of such sub-triangles can be described in terms of the Jarlskog-like invariants of CP violation ${\cal J}^{ij}_{\alpha\beta}$, and their small differences signify slight unitarity violation of the PMNS matrix $U$.
Neutrino non-standard interactions (NSIs) have been actively investigated both theoretically and experimentally in the past. Yet null signals of any new physics at colliders and from low-energy precision measurements have gradually motivated the investigation of new physics model-independently. Effective Field Theories (EFTs) provide such a systematic and model-independent framework. In this talk, working within the EFT framework, I will present our recent results on both neutral- and charge-current neutrino NSIs from neutrino oscillation experiments [1] and precision cosmology [2].
Refs:
[1] https://arxiv.org/abs/2011.14292
[2] https://arxiv.org/abs/2101.10475
In this talk, I will explore a surprising connection between speculative issues in elementary particle physics and the Sun. I will show how the extreme sensitivity of nuclear reaction Coulomb barrier penetration at the low energies of the solar core and the recent observation of the CNO neutrinos from the Sun by the Borexino collaboration could be leveraged to probe aspects of the non-standard interactions involving light mediators recently invoked to explain anomalies in short baseline neutrino experiments. Moreover, with an improved determination of solar metallicity, and a more precise measurement of the CNO flux it is very likely that our limits on the mass and the coupling of the non-standard mediators will improve even more.
Neutrino electromagnetic properties are import windows in neutrino physics to go beyond the Standard Model. The coherent elastic neutrino-nucleus scattering process is a powerful probe of the neutrino electromagnetic properties, which was first observed in 2017 at the COHERENT experiment by the cesium-iodide (CsI) detector and later in 2020 at the argon (Ar) detector.
In this talk, we present the constraints of neutrino electromagnetic properties from COHERENT CsI and Ar data, including the neutrino charge radii, millicharges and magnetic moments. The combined CsI and Ar limits are also obtained, and compared with other experimental results. We show that the COHERENT data can provide competitive constraints of the neutrino charge radii, in particular for the muon neutrino related components.
In this talk, I summarize the investigation revolving around neutrino physics within the framework of extended theories of gravity. By relying on the covariant reformulation of Pontecorvo’s formalism, one can evaluate the oscillation probability of neutrinos propagating in static spacetimes described by gravitational actions quadratic in the curvature invariants. In particular, it is shown that neutrino oscillations are sensitive to the violation of the strong equivalence principle (SEP) in such a way that the aforesaid occurrence leads to phenomenologically testable implications. Indeed, it is possible to check that the parameter quantifying SEP directly appears in the expression of the oscillation phase, and as long as this correction is non-vanishing the flavor transition probability is different from the flat case.
By way of illustration, I specialize the above study to specific extended theories of gravity in order both to quantify SEP violation and to understand how the characteristic free parameters of these models affect the neutrino phase. In passing, the possibility to fix new bounds on these parameters (and hence to constrain extended theories of gravity) is also discussed.
The observation of coherent elastic neutrino-nucleus scattering performed by the COHERENT experiment with cesium iodide in 2017 and with liquid argon in 2020, represents an innovative and powerful tool for investigating non-standard interactions not included in the Standard Model and interactions mediated by yet to be discovered light neutral vector bosons.
We present new constraints on three different models of light mediators, namely universal, B-L and Lµ − Lτ models, involving a light vector Z’ mediator, by exploiting the data recently released by the COHERENT Collaboration. We compare the results obtained from a combination of the cesium-iodide and argon data sets with the limits obtained by other experiments, and with the parameter region that could explain the anomalous magnetic moment of the muon.
The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is a 26-ton Gd-doped water Cherenkov detector installed in the Booster Neutrino Beam (BNB) at Fermilab. The primary physics goal of ANNIE is to measure the neutron yield from νμ interactions as a function of Q2 in order to constrain neutrino-nucleus interaction theoretical models. Identifying and counting final state neutrons provides a new experimental handle to study systematic uncertainties related to the neutrino energy reconstruction in oscillation experiments. To achieve that goal ANNIE will make the first use of the novel Large Area Picosecond Photodetectors (LAPPDs) and demonstrate the feasibility of this technology as a new tool in physics experiments. In this talk we present an overview of the experiment and the first beam commissioning and calibration data.
MINERvA is a neutrino scattering experiment at Fermilab that utilizes the intense neutrino beam from the NuMI beamline and a finely segmented scintillator-based tracking detector to measure neutrino cross sections and study nuclear effects with various nuclear targets. MINERvA has results using both its low- energy and medium energy data sets. These results cover both exclusive and inclusive channels off multiple nuclei for muon neutrinos and anti-neutrinos and will benefit long-baseline neutrino oscillation experiments that require this precise understanding of neutrino-nucleus interactions. A summary of recent results from MINERvA will be presented.
MicroBooNE is a liquid argon time projection chamber that operates in the Booster Neutrino Beam at Fermilab. The detector provides high-resolution imaging of neutrino interactions with a low threshold and full angular coverage. Thanks to a high expected event rate and several years of continuous operation, the MicroBooNE collaboration has obtained the world's largest dataset of neutrino-argon scattering events. A detailed understanding of these interactions, especially the impact of nuclear physics effects, will be critical to the success of future precision neutrino oscillation efforts, particularly the argon-based Deep Underground Neutrino Experiment (DUNE) and the Short-Baseline Neutrino (SBN) program. This talk presents an overview of the latest neutrino-argon cross section measurements in MicroBooNE. Particular emphasis is given to recent studies of charged-current interactions leading to final states containing zero pions and one or more protons.
While the galactic core is 25,000 light years away but the number of stars there is immense making it the 2nd brightest neutrino source in the sky other than our Sun. The collection power of a gravitational Lens using our Sun is the most efficient way to focus this and unlike the light gravitational lens at 500 AU since the neutrino has mass its expected location is 20 to 40 AU, reachable with current and future planned NASA deep space probes. We are developing ways to make a neutrino gravitational lens to both image the galactic core in stellar neutrinos, and also this can be a new way to measure the mass of the neutrino.
The Sudbury Neutrino Observatory experiment (SNO) has performed a variety of measurements of neutrino and cosmic ray interactions, including the first observation of solar neutrino flavor change that confirmed that neutrinos have mass. Several new analyses using the SNO dataset collected between 1999 and 2006 have recently been completed, including tests of Lorentz invariance, constraints on neutrino lifetime, measurements of atmospheric neutrino– and muon-induced neutron production, and searches for $hep$ solar neutrinos and the diffuse supernova neutrino background (DSNB). We will discuss these results with an emphasis on the most recent $hep$ and DSNB analysis, and comment on ongoing work.
We present a phenomenological concordance scenario with a relativistic jet for the Tidal Disruption Event (TDE) AT2019dsg, which has been proposed as source of the astrophysical neutrino event IceCube-191001A. Noting that AT2019dsg is one of the brightest (and few) TDEs observed in X-rays, in our work we connect the neutrino production with the X-rays: an expanding cocoon causes the progressive obscuration of the X-rays emitted by the accretion disk, while at the same time it provides a sufficiently intense external target of back-scattered X-rays for photo-pion production off protons. We also describe the late-term emission of the neutrino (about 150 days after the peak), by scaling the production radius with the black body radius. Our energetics and assumptions for the jet and the cocoon are compatible with expectations from numerical simulations of TDEs. About 0.26 neutrino events are predicted in the right energy range in IceCube.
We study the connection between the two indications of physics beyond the Standard Model (SM): the masses and mixing of neutrinos and the existence of dark matter (DM). The most attractive proposal for the origin of neutrino mass, the type I seesaw mechanism, can also account for matter-antimatter asymmetry via leptogenesis. We show that a minimal extension of type I seesaw models can also provide a portal to dark matter. As a concrete example, we study a minimal type I seesaw model with a right-handed neutrino portal to a minimal dark sector containing the dark matter candidate particle. In the minimal model, the parameters of the seesaw sector are fixed by neutrino oscillation data and leptogenesis. With the seesaw parameters fixed, we explore the portal and dark parameters required to obtain the observed DM relic abundance. Within this framework, we show how DM may be directly related to neutrino physics.
I will discuss our recent work on a simple scoto-seesaw model that accounts for dark matter and neutrino masses with spontaneous CP violation. This is achieved with a single horizontal $\mathcal{Z}_8$ discrete symmetry, broken to a residual $\mathcal{Z}_2$ subgroup responsible for stabilizing dark matter. CP is broken spontaneously via the complex vacuum expectation value of a scalar singlet, inducing leptonic CP-violating effects. We find that the imposed $\mathcal{Z}_8$ symmetry pushes the values of the Dirac CP phase and the lightest neutrino mass to ranges already probed by ongoing experiments.
Determining the leptonic CP-violation is one of the main objectives of the neutrino oscillation experiments. Long-baseline (LBL) experiments are expected to play a crucial role in this direction. Two LBL experiments T2K and NO$\nu$A are already playing a leading role in addressing this issue. Apart from this, a few highly sophisticated LBL experiments like DUNE, T2HK, and ESS have also been planned to address this issue as well as the remaining unknown issues. In this talk, I will explore the current status and future prospects of discovering the leptonic CP-violation in the current and future LBL experiments in presence of an eV-scale light sterile neutrino.
The conference goes on break on Saturday and Sunday. It will continue on Monday 22nd
The conference goes on break on Saturday and Sunday. It will continue on Monday 22nd
We analyze the effects of a Violation of Equivalence Principle (VEP) on neutrino oscillations, focusing on the recently released IceCube data on atmospheric neutrino fluxes. We obtain the strongest constraints up to date on the parameter space of VEP in the context of neutrino physics with a benchmark choice for the coupling between neutrinos and gravitational field. We also study the effect of VEP on the flavor composition of astrophysical neutrinos, stressing the interplay with the basis in which VEP is diagonal. We find that for some choices of such basis the flavor ratio measured by IceCube can probe VEP and we compare with the sensitivities of IceCube-Gen2 as well.
Active galactic nuclei (AGN) are among the most promising neutrino source candidates, because of their potential to accelerate cosmic rays and also because of the dense photon fields present in their relativistic jets. In support of this hypothesis, IceCube has already observed several high-energy events from the direction of known blazar AGN like TXS 0506+056 and, more recently, PKS 1502+106. Through numerical modeling, we can show that these individual IceCube events can be explained through photohadronic interactions of cosmic rays accelerated in the jet up to ~PeV energies. These same interactions can self-consistently reproduce the multi-wavelength spectra observed simultaneously to those neutrino events. By applying the same model to the entire AGN population, I will show that the diffuse IceCube flux can, under certain conditions, be fully explained by this source class, specifically from the sub-class of low-luminosity BL Lacs. On the other hand, it is also possible that AGN accelerate cosmic rays up to ultra-high (~EeV) energies. In this case, detailed modeling shows that the AGN population can account for the entire observed spectrum of ultra-high-energy cosmic rays, while obeying the current IceCube stacking limits in the PeV regime. We can then expect potentially large amounts of EeV neutrinos, produced both in the source and during propagation (cosmogenic). I will argue that the flux of EeV neutrinos produced inside AGN jets can in fact outshine the cosmogenic contribution, a conclusion that has important implications for the search strategy of future radio neutrino telescopes.
Gamma-Ray Bursts (GRBs) are among the brightest transients in our universe. Given the large amount of energy they release they have been long discussed as sources of ultra-high-energy cosmic rays (UHECR) - A hypothesis which is challenged by current IceCube neutrino limits. Assuming GRBs to power the UHECR flux, we study different engine realisations in multi-collision internal shock models and compute the in-source UHECR composition required to fit the observed spectra. Explicitly calculating the corresponding prompt and cosmogenic neutrino fluxes for the different scenarios, we show how (future) experiments might be used to discriminate between different scenarios and which parameter space is ruled out by neutrino observations.
Ultra-high-energy cosmic rays (UHECRs) interact with pervasive photons during propagation. These interactions produce neutrinos, which can provide valuable insights on the elusive sources of UHECRs as well as on the composition of the highest-energy radiation. In this talk I will present realistic predictions for this cosmogenic flux, obtained through fits to UHECR measurements. In light of these results, I will discuss the prospects for detecting cosmogenic neutrinos with current and next-generation neutrino telescopes.
The T2K neutrino experiment in Japan started data taking in 2010 and obtained a first indication of CP violation in neutrino oscillations. To obtain better sensitivity, T2K will accumulate more statistics with a higher intensity beam and an upgraded near detector. The upgraded off-axis near detector (ND280) will allow us to reduce systematic uncertainties in the number of predicted events at Super-Kamiokande and to constrain the neutrino interaction cross section models. The upgraded detector will have the full polar angle coverage for muons produced in neutrino charged current interactions, a low threshold for proton detection and will be able to measure neutrons using time-of-flight due to a good timing performance. Thanks to these new capabilities, the upgrade of ND280 will measure the energy spectra of muon neutrinos and antineutrinos with an unprecedented level of accuracy, and the near-to-far detector extrapolation of systematics constrains will be much less model dependent and therefore more reliable.
A novel 3D highly granular scintillator detector called SuperFGD of a mass of about 2 tons was adopted as an upgraded ND280 fully-active neutrino target and a 4\pi detector of charged particles from neutrino interactions. It will consist of about two millions of small optically-isolated plastic scintillator cubes with a 1 cm side. Each cube is read out in the three orthogonal directions with wave-length shifting fibers coupled to compact photosensors, micro pixel photon counters. Several SuperFGD prototypes tested in beams with charged particles and neutrons demonstrated good performance. It is planned that SuperFGD installed into the ND280 magnet will be ready to accept the beam in December 2022. In this talk, the results of the beam tests of the SuperFGD prototypes, obtained parameters and current status of the detector construction will be reported. The physics program of SuperFGD and its ability for further reduction of largest systematic uncertainties in oscillation analysis based on realistic assumptions extracted from the present T2K results will be described.
The atmospheric neutrino flux represents a continuous source that can be exploited to infer properties about Cosmic Rays and neutrino oscillation physics. The JUNO observatory, a 20 kt liquid scintillator (LS) currently under construction in China, will be able to detect atmospheric neutrinos down to lower energies, with respect to Cherenkov detectors, given the large fiducial volume and the high light yield. The light produced in neutrino interactions with the LS will be collected by a double-system of photosensors: 18.000 20" PMTs and 25.000 3" PMTs. The LS detector is surrounded by a Cherenkov water pool, equipped with 2.400 20" PMTs, which is designed to reject atmospheric muons with high efficiency. The rock overburden above the experimental hall is around 700 m and the experiment is expected to see the first data in 2022.
In this work, potential JUNO measurements in the field of atmospheric neutrinos are evaluated. A sample of Monte Carlo events has been generated from theoretical models of the atmospheric neutrino flux, through the GENIE software. To evaluate the JUNO performances, the events have been processed by a full GEANT4 - based simulation, which propagates all the particles and the light inside the detector. The different time evolution of light on the PMTs allows to discriminate the flavor of the primary neutrinos. To reconstruct the time pattern of events, the signals from 3" PMTs only have been used, because of the excellent time resolution. A probabilistic unfolding method has been used, in order to infer the primary neutrino energy spectrum by looking at the detector output. JUNO will be particularly sensitive in the energy range (100-1000) MeV, where neutrino-induced events can be fully contained within the instrumented volume. The energy region is particularly interesting, for several reasons: first, the flavor oscillation effects due to the large neutrino mass-splitting are maximized; then, the region covers an area of interest for other studies too, like the search for nucleon decay and relic supernovae neutrinos.
In spite of the extensive search for the detection of the dark matter (DM), experiments have so far yielded null results: they are probing lower and lower cross-section values and are touching the so-called neutrino floor. A way to possibly overcome the limitation of the neutrino floor is a directional sensitive approach: one of the most promising techniques for directional detection is nuclear emulsion technology with nanometric resolution. The NEWSdm experiment, located in the Gran Sasso underground laboratory in Italy, is based on novel nuclear emulsion acting both as the Weakly Interactive Massive Particle (WIMP) target and as the nanometric-accuracy tracking device. This would provide a powerful method of confirming the Galactic origin of the dark matter, thanks to the cutting-edge technology developed to readout sub-nanometric trajectories. In this talk we discuss the experiment design, its physics potential, the performance achieved in test beam measurements and the near-future plans. After the submission of a Letter of Intent, a new facility for emulsion handling was constructed in the Gran Sasso underground laboratory which is now under commissioning. A Conceptual Design Report is in preparation and will be submitted in Summer 2021.
Upon the neutrino discovery by Reines & Cowan (1956), they also paved the ground behind much of today’s neutrino detection technology. Large instrumented volumes for neutrino detection have been achieved via a key (implicit) principle: detection medium transparency and/or high purity. Much of that technology has yielded historical success, including several Nobel prizes, where the discovery of the neutrino oscillation phenomenon is the latest example. Despite the stunning success, the “transparent technology” like the pioneering liquid scintillator detectors are known to suffer from key limitations such as little (or no) topological particle identification (PID) ability, typically enabling active background rejection. Solving this while keeping the detector scalability has long remained one of the main challenges in the field. Still today, many of those otherwise overwhelming backgrounds can only be reduced via an expensive passive shielding strategy, including the advent for deep underground laboratories. In this talk, we will introduce the novel LiquidO technology (released since mid-2019 by an international proto-collaboration and still under active R&D) whose rationale exploits detection medium extreme opacity, thus breaking with the need for transparency, to yield unprecedented event-wise PID which may reduce dramatically the need for passive shielding.
SND@LHC is a proposed, compact and stand-alone experiment to perform measurements with neutrinos produced at the LHC in an hitherto unexplored pseudo-rapidity region of 7.2<$\eta$<9.6, complementary to all the other experiments at the LHC. The experiment is to be located 480 m downstream of IP1 in the unused TI18 tunnel. The detector is composed of a hybrid system based on an 800 kg target mass of tungsten plates, interleaved with emulsion and electronic trackers, followed downstream by a muon system. The configuration allows efficiently distinguishing between all three neutrino flavours, opening a unique opportunity to probe physics of heavy flavour production at the LHC in the region that is not accessible to ATLAS, CMS and LHCb. The detector concept is also well suited to searching for Feebly Interacting Particles via signatures of scattering in the detector target. The first phase aims at operating the11detector throughout LHC Run 3 to collect a total of 150 fb$^{−1}$.
The SHiP Collaboration has proposed a general-purpose experimental facility operating in beam dump mode at the CERN SPS accelerator with the aim of searching for light, long-lived exotic particles of Hidden Sector models. The SHiP experiment incorporates a muon shield based on magnetic sweeping and two complementary apparatuses.
The detector immediately downstream of the muon shield is optimised both for recoil signatures of light dark matter scattering and for tau neutrino physics. The second one aims at measuring the visible decays of hidden sector particles to both fully reconstructible final states and to partially reconstructible final states with neutrinos, in a nearly background free environment.
Using the high-intensity beam of 400 GeV protons, the experiment is capable of integrating 2 x 10ˆ20 protons in five years, which allows probing heavy neutrinos with GeV-scale masses at sensitivities that exceed those of existing and projected experiments. The sensitivity to light dark matter reaches well below the elastic scalar Dark Matter relic density limits in the range from a few MeV/cˆ2 up to 200 MeV/cˆ2. The tau neutrino deep-inelastic scattering cross-sections will be measured with a statistics a thousand times larger than currently available, with the extraction of the F4 and F5 structure functions, never measured so far.
An overview of the SHiP neutrino program will be reported at this conference.
The Future Circular Collider (FCC) is proposed as a post-LHC particle collider at CERN and consists of different steps. The first step of the FCC (FCC-ee) is a high-luminosity, high-precision lepton collider located in the same tunnel as a possible precursor to a hadron collider, and complementary to it. The ultimate goal, FCC-hh, is a 100 TeV hadron collider, colliding protons and heavy-ions, with a center of mass energy seven times that of the LHC, an energy step similar to the one from the Tevatron to the LHC. A hadron-lepton collider (FCC-eh), operating with the FCC-hh, could be the finest microscope for studying quark-gluon interactions and possible further substructure of matter.
One of the most interesting searches that will be possible at the FCC concerns heavy neutrinos, or heavy neutral leptons. These hypothetical new particles hold an incredible potential, since they could provide answers to many interesting open questions in the standard model (SM) of particle physics, from neutrino masses to the matter-antimatter imbalance of the Universe, including offering a plausible Dark Matter candidate.
At the FCC (ee, hh, eh) a large parameter space will be within reach for Heavy Neutrinos. The FCC-ee running at the Z-Pole will be unbeatable: heavy neutrino produced in Z decays with low-mixing with the regular neutrinos, all the way to the domain of type-1 seesaw models, could give rise to characteristic, and essentially background free, long-lived signatures in the detectors. When the decay lengths of these new particles is long enough, neutrino oscillations might even be studied, and offer limited sensitivity for tests of Lepton Number Violation. The initial state flavor and charge is known at FCC-hh and FCC-eh, and therefore they will offer tests of lepton-flavor violation and Lepton Number violation in a domain of somewhat larger mixing angles.
This is the right time to start benchmarking the most interesting physics process to study at the different phases of the FCC, exploring the corresponding detector requirements; during this process heavy neutrinos will take a central stage. The complementarity of the three different stages of the FCC provides unique potential to discover and pin down these particles, and maybe solving long-standing problems of the SM. This talk will describe the current landscape and possible areas to contribute to in the next years.
We investigate the sensitivity of electron-proton (ep) colliders for charged lepton flavor violation (cLFV) in an effective theory approach, considering a general effective Lagrangian for the conversion of an electron into a muon or a tau via the effective coupling to a neutral gauge boson or a neutral scalar field. For the photon, the Z boson and the Higgs particle of the Standard Model, we present the sensitivities of the LHeC for the coefficients of the effective operators, calculated from an analysis at the reconstructed level. As an example model where such flavor changing neutral current (FCNC) operators are generated at loop level, we consider the extension of the Standard Model by sterile neutrinos. We show that the LHeC could already probe the LFV conversion of an electron into a muon beyond the current experimental bounds, and could reach more than an order of magnitude higher sensitivity than the present limits for LFV conversion of an electron into a tau. We discuss that the high sensitivities are possible because the converted charged lepton is dominantly emitted in the backward direction, enabling an efficient separation of the signal from the background.
Blazars are a subclass of active galactic nuclei (AGNs) that have a relativistic jet with a small viewing angle towards the observer. Recent results based on hadronic scenarios have motivated an ongoing discussion of how a blazar can produce high energy neutrinos during a flaring state and which scenario can successfully describe the observed gamma-ray behavior. Markarian 421 (Mrk 421) is one of the closest and brightest objects in the extragalactic gamma-ray sky and showed flaring activity over a 14-days period in 2010 March. In this work, we describe the performed analysis of Fermi-LAT data from the source focused on the MeV range (100 MeV–1 GeV), and study the possibility of a contribution coming from the pγ interactions between protons and MeV SSC target photons to fit the very high energy (VHE) gamma-ray emission. The fit results were compared with two leptonic models (one-zone and two-zone) using the Akaike Information Criteria (AIC) test, which evaluates goodness-of-fit alongside the simplicity of the model. In all cases, the photohadronic model was favored as a better fit description in comparison to the one-zone leptonic model, and with respect to the two-zone model in the majority of cases. Our results show the potential of a photohadronic contribution to a lepto-hadronic origin of the gamma-ray flux of blazars. Future gamma-ray observations above tens of TeV and below 100 MeV in energy will be crucial to test and discriminate between models.
A small fraction of GRBs with available data down to soft X-rays ( ~0.5 keV) have been shown to feature a spectral break in the low energy part of their prompt emission spectrum. The overall spectral shape is consistent with optically thin synchrotron emission from a population of marginally fast cooling particles. If the radiating particles are electrons, this interpretation implies relatively weak magnetic fields and large emitting regions to limit, respectively, synchrotron and inverse Compton cooling. Both requirements are, however, in tension with the idea of a compact region producing the variable GRB prompt emission. In this work we consider the hadronic scenario and investigate the idea that the prompt emission originates from relativistic protons that radiate synchrotron in the marginally fast cooling regime. We compute the source parameters required for such a scenario to work and investigate how additional processes, namely photohadronic interactions and gamma-gamma pair production, contribute to the overall spectrum. We numerically compute the observed photon spectra and calculate the expected high-energy neutrino emission following the assumptions of this work.
Neutrinos are puzzling particles that could answer many of the open questions about our Universe. Unlike any other observed particle, the flavor of neutrinos can feedback into itself in a neutrino-dense astrophysical environment. Such neutrino self-interaction leads to intriguing “fast” flavor conversions that can develop within a few nanoseconds in the core of core-collapse supernovae and compact binary mergers. Inevitably, since neutrinos are copiously produced in the merger of two neutron stars, fast neutrino conversions are predicted to be ubiquitous in neutron star merger remnants with potentially major implications on the nucleosynthesis of the elements heavier than iron, and therefore on the related kilonova electromagnetic emission. We present the first multi-dimensional numerical modeling of the neutrino flavor evolution above the merger remnant disk and discuss the possible implications that neutrino flavor conversions could have on the associated kilonova observed at Earth.
In the work presented here, I have developed a new numerical framework to include neutrino conversions in a simplified model that resembles a binary neutron star merger remnant. Although an approximation, this model is the first multi-dimensional solution of such an astrophysical system that takes into account the detailed neutrino advection and neutrino flavor conversion physics that has not been explored in past studies. This work constitutes a major step forward in the exploration of the role of neutrinos in compact merger remnants. Our findings suggest that complete modeling of the neutrino flavor conversion physics should be taken into account in order to make robust predictions for the electromagnetic emission expected by the merger remnant and its aftermath.
Several theories of particle physics beyond the Standard Model consider that neutrinos can decay. I discuss the sensitivity of the upcoming neutrino telescope KM3NeT-ORCA to this scenario. I show that it could improve the current bounds coming from oscillation experiments, where three-neutrino oscillations have been considered, by roughly two orders of magnitude. I also discuss the robustness of the experiment to the standard oscillation parameters and the neutrino mass ordering in presence of invisible neutrino decay.
Starburst Galaxies are known as “reservoirs” of high-energy cosmic rays which potentially could contribute to the astrophysical diffuse neutrino flux measured by IceCube. In this work, we go beyond the standard prototype-based approach, and investigate a model based on a data-driven blending of spectral indexes, thereby capturing the observed changes in the properties of individual emitters. We then perform a multi-messenger analysis considering the extragalactic gamma-ray background (EGB) measured by Fermi-LAT and the IceCube data samples. Remarkably, we find that, the spectral index blending allows starburst galaxies to account for up to 40% of the HESE events at 95.4 % C.L., while satisfying the limit on the non-blazar EGB component. In broad terms, our analysis points out that a better modeling of astrophysical sources could alleviate the tension between neutrino and gamma-ray data interpretation.
Largest Solar Flare did burst on Earth hardest gamma photons of pion nature. The associated charged pion decay must also shine hard muon and electron neutrinos. Their detection and their flavor might be observable in largest present or future underground detectors if, at flare peak, they are overcoming the steady atmospheric noise. The present Super Kamiokande neutrino detector recently amplified by Gadolinium, might record, in years, the relic cosmic Supernovae noises at tens MeV energy; at same tens MeV energies, the brightest Solar neutrino flare might be observable by one or few events. Hyper Kamikande megaton will surpass the SK mass, better allowing a detection of Solar electron, muon anti-neutrino flare at tens and hundreds MeV. Finally the Icecube inner core, whose tens megaton volume and whose energy threshold might reach few or ten GeV ones, might also rarely record brightest neutrinos both of electron and muon nature possibly tracking also their solar arrival direction. Tau flavor neutrino presence by flight mixing is almost undetectable because soft solar flare spectra and the large tau mass threashold, but in principle it might be somehow observed.
The Taishan Antineutrino Observatory (JUNO-TAO) is a ton-level liquid scintillator detector at 30-35 meters from the Taishan reactor and it is a satellite detector of the JUNO Observatory.
It aims to measure the reactor neutrino spectrum and to provide model independent inputs for the neutrino mass hierarchy. To reach an energy resolution better than 2%, the scintillation light produced in the liquid scintillator is detected by about 4100 Silicon photomultipliers (SIPMs) having a >50% photon detection efficiency.
SIPMs should fit several requests: a low radioactivity, less than 4.4 Bq/kg, 6.3 Bq/kg and 1 Bq/kg for Uranium, Thorium and Potassium, respectively; high and uniform photon detection efficiency; a low value of dark noise at -50 °C, the operative temperature of the detector.
A R&D on SIPMs is in progress to find the best solution for the JUNO-TAO detector.
In this talk, an overview of the R&D will be reported with emphasis on the requirements of SIPMs and ongoing work related to their characterizations.
JUNO is a 20 kt liquid scintillator detector under construction in Jiangmen, China, whose goal is to determine the neutrino mass hierarchy. Decay of radioactive isotopes in the liquid scintillator can mimic neutrino signal events. In order to meet the stringent requirements on the radiopurity of the liquid scintillator in JUNO experiment, the OSIRIS pre-detector is being designed to monitor the liquid scintillator during the several months of filling the large volume of JUNO. OSIRIS will contain 20 ton of scintillator and will be equipped with 76 20-inch PMTs. The data acquisition system will have no global hardware trigger: instead, each PMT will provide a data-stream composed of the digitized PMT pulses, each containing a time stamp. Based on the latter, dedicated software will organize these data streams into events by sorting the time stamps and apply trigger logics. To optimize the trigger conditions, physics events are generated from the Geant4-based OSIRIS simulation software. Then the output of photon hits on all PMTs are transferred into our DAQ simulation software where dark counts are also simulated. Afterwards, different trigger conditions are applied in the event builder. This talk will discuss the final trigger setup as a function of $^{14}$C beta-decay event rate and dark rates of PMTs. Our goal is to achieve the optimal trade-off of maintaining a low dark noise event rate with a high trigger efficiency to detect $^{14}$C events.
Future neutrino observatories, like the Deep Underground Neutrino Experiment (DUNE),
will be sensitive to supernovae and solar neutrinos of low energies. These neutrinos offer a unique
look inside stars and stellar explosions. Inside the DUNE liquid argon time projection chamber,
low-energy electron neutrinos will produce visible electrons. In this talk, we will present a
preliminary study of delta-rays that have similar energies to the electrons scattered by low-energy
astrophysical neutrinos. Unlike neutrinos, delta-rays are a well understood "standard candle."
Furthermore, they provide ample statistics, a valuable feature in the otherwise quiet underground
environment. We will outline how they can be used to calibrate DUNE's response to < 30 MeV
electrons in situ.
Recent neutrino oscillation experiments have ushered in a new era with precisionmeasurements employed in the search for CP violation and mass hierarchy. The Deep UndergroundNeutrino Experiment (DUNE) is a next generation long-baseline neutrino experiment hosted by the U.S. Department of Energy's Fermilab. The single-phase liquid argon far-detector prototype (ProtoDUNE-SP) at the CERN neutrino platform is a critical milestone for the DUNE experiment. It serves as a prototype to validate the technology for the 10-kton fiducial mass liquid argon detectors for the DUNE experiment. The primary physics goal of ProtoDUNE-SP is to measure the hadron-argon cross-sections at unprecedented precision. ProtoDUNE-SP was exposed to a varietyof test-beam particles (protons, pions, kaons, muons, and electrons) in a broad range of momenta, from 0.3 - 7 GeV/c. This provides rich data to study the hadron-argon interactions in a liquid argondetector. In this talk, I will present our progress on the proton-argon cross-section measurement, including the selection of beam protons, space charge calibration, calorimetric reconstruction, and the latest update of the analysis.
The ESS neutrino Super Beam project (ESS$\nu$SB) aims at the production of an intense neutrino beam by using the 5 MW average power proton beam from the ESS facility currently under construction in Lund (Sweden). In the present work, we show the results of the Genetic Algorithm applied to the design of the ESS$\nu$SB target station. The impact of this optimization method on the physics reach of the experiment, especially on the precision which can be achieved in the measurement of the neutrino oscillation CP-violating phase $\delta_{CP}$, is discussed. The ESS$\nu$SB project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 777419.
China is currently seeing a rise of underground laboratories and particle accelerators on its mainland. In this talk, we discuss the prospects of building a next-generation accelerator-based neutrino oscillation experiment by utilizing the laboratory sites that are available in China. We consider the potential candidates for the neutrino beam and detector facilities and examine their suitability to study CP violation and physics beyond the Standard Model in a neutrino oscillation experiment. As an example, we present a case study on an experimental configuration where an accelerator-based neutrino beam is produced at the injector chain of the Super Proton-Proton Collider while placing the neutrino detector in the China JinPing underground Physics Laboratory. Our findings highlight the importance of including a tau neutrino physics program in such an experiment.
After the successful experimental confirmation of the phenomenon of neutrino oscillation, the major goal of the neutrino experiments has mainly shifted to the search for leptonic CP-violation (CPV), determination of neutrino mass ordering and the precision measurement of the oscillation parameters.
Leptonic CPV, if it can be established, can offer a crucial ingredient in explaining the puzzle of the baryon asymmetry in the observed universe through an elegant mechanism called leptogenesis. Determination of mass ordering and precision measurements will shed light on the plausible set of models for neutrino mass generation. All these require the investigation of neutrino oscillation over a wide range of the ratio ($L/E$) of neutrino propagation length $L$ and neutrino beam energy $E$. This will help in gathering information over several oscillation maxima to search for the physics issues
mentioned above. Deep Underground Neutrino Experiment (DUNE) is a next generation long baseline experiment that is expected to see the second oscillation maximum (SOM) in addition to the first oscillation maximum (FOM). We discuss how at the SOM, the CP sensitivity can potentially become larger compared to that of FOM. We write a new $\Delta \chi^{2}$ code that estimates, for the first time in literature, the sensitivity of DUNE to probe the SOM in its projected data.
Euclid is a European Space Agency mission on satellite, whose aim is to investigate the so called “dark universe” (that is, dark matter and dark energy) and thus strongly constrain the main cosmological parameters, including the sum of neutrino masses. For this purpose, an extensive calibration of all the telescope elements is required. I’ve worked on the in-flight flux calibration procedure of the Euclid NISP spectrograph: the same sources in the sky, observed in different positions on the focal plane, are detected with a different number of counts because of the non-uniformity in the transmission of light introduced by the telescope internal optics. Simulations are needed to choose the best combination of observed sky area and pointings, so that the required accuracy on this self-calibration procedure can be reached. I’ll briefly illustrate the procedure we studied for this purpose and its preliminary results for a simplified scenario.
The preference of the normal neutrino mass ordering from the recent cosmological constraint and the global fit of neutrino oscillation experiments does not seem like a wise choice at first glance since it obscures the neutrinoless double beta decay and hence the Majorana nature of neutrinos. Contrary to this naive expectation, we point out that the actual situation is the opposite. The normal neutrino mass ordering opens the possibility of excluding the higher solar octant and simultaneously measuring the two Majorana CP phases in future 0ν2β experiments. Especially, the funnel region will completely disappear if the solar mixing angle takes the higher octant. The combined precision measurement by the JUNO and Daya Bay experiments can significantly reduce the uncertainty in excluding the higher octant. With a typical O(meV) sensitivity on the effective mass |mee|, the neutrinoless double beta decay experiment can tell if the funnel region really exists and hence exclude the higher solar octant. With the sensitivity further improved to sub-meV, the two Majorana CP phases can be simultaneously determined. Thus, the normal neutrino mass ordering clearly shows phenomenological advantages over the inverted one.
We study the properties of the Cabibbo suppressed quasielastic production of $\Lambda$ and $\Sigma$ hyperons in antineutrino interactions with nuclei using the NuWro Monte Carlo generator. Few events of this kind have been observed in previous experiments and the model is built exploiting the SU(3) quark flavour symmetry. We study the results of introducing symmetry breaking and the second class current into this model. Nuclear effects are included through final state interactions and a test potential affecting the hyperon. This potential reduces the inclusive hyperon production rate through reabsorption and a large fraction of $\Sigma$ baryons are converted to $\Lambda$ through reinteractions.
In this presentation the novel phenomenon of heavy neutrino-antineutrino oscillations is discussed as well as the QFT framework to describe it. Easy to implement formulae are presented which can be used to obtain the expected rate of lepton number conserving/violating displaced vertex events at colliders and the feasibility to observe oscillations for different models.
Neutrino decay modifies neutrino propagation in a unique way; not only is there flavor changing as there is in neutrino oscillations, there is also energy transport from initial to final neutrinos. The most sensitive direct probe of neutrino decay is currently IceCube which can measure the energy and flavor of neutrinos traveling over extragalactic distances. For the first time we calculate the flavor transition probability for the cases of visible and invisible neutrino decay,including the effects of the expansion of the universe, and consider the implications for IceCube. As an example, we demonstrate how neutrino decay addresses a tension in the IceCube data.
The next generation of neutrino telescopes, including Baikal-GVD, KM3NeT, P-ONE, TAMBO, and IceCube-Gen2, will be able to determine the flavor of high-energy astrophysical neutrinos with 10% uncertainties. With the aid of future neutrino oscillation experiments --- in particular JUNO, DUNE, and Hyper-Kamiokande --- the regions of flavor composition at Earth that are allowed by neutrino oscillations will shrink by a factor of ten between 2020 and 2040. We critically examine the ability of future experiments and show how these improvements will help us pin down the source of high-energy astrophysical neutrinos and a sub-dominant neutrino production mechanism with and without unitarity assumed. As an illustration of beyond-the-Standard-Model physics, we also show that the future neutrino measurements will constrain the decay rate of heavy neutrinos to be below $2\times 10^{-5}~$$m$/eV/s assuming they decay into invisible particles.
The Glashow resonance, which corresponds to the production of a W boson from the resonant interaction between a high-energy electron antineutrino and an electron at rest, offers us a unique signature to disentangle electron antineutrinos from the total high-energy astrophysical neutrino flux. Identification of neutrino flavors in neutrino telescopes is important to the study of production mechanisms and interactions of high-energy neutrinos in astronomical sources and during their propagation. At the same time, a great number of neutrino telescopes are advancing towards a better understanding of the Universe in highest energies. In this talk, I will discuss the prospect of observing Glashow resonant events in current experiments such as IceCube and future experiments which aim to observe Earth-skimming or mountain-penetrating tau neutrinos.
The main goals of the Deep Underground Neutrino Experiment (DUNE) are to measure CP violation in the lepton sector, to make precise measurements of neutrino oscillation parameters, to observe supernova burst neutrinos and to detect rare processes such as proton decay. To fulfill these goals, DUNE will use a highly capable suite of near detectors that work together to constrain flux and cross section uncertainties, which are the dominant sources of uncertainties in oscillation measurements. The near detectors will also be sensitive to numerous signals of physics beyond the standard model. The DUNE near detector complex will consist of a liquid argon TPC, ND-LAr, a magnetized high pressure gas argon TPC surrounded by a calorimeter, ND-GAr, and an on-axis neutrino detection system, SAND whose primary purpose is to monitor the beam with 1% precision. In this talk, I will present an overview of the DUNE near detector suite and its expected capabilities.
The combination of recent developments in liquid scintillator, photodetection technology, and reconstruction techniques have made possible the concept of a large-scale neutrino detector that can distinguish Cherenkov and scintillation light. THEIA is a proposed multi-kton experiment that would be pioneering in exploiting the innovative concept of hybrid optical detectors, with the potential to pursue an extremely broad physics program.
If placed at SURF, THEIA will be complementary to DUNE in constraining the oscillation parameters using a different detector technology and target nucleus. The expected sensitivity of THEIA to both $δ_\text{CP}$ and to the neutrino mass ordering is comparable to that of a single DUNE module under the assumption of a similar geometry. At the same time, the low energy threshold and efficient neutron tagging provided by the scintillator target expands the physics reach of THEIA to cover solar and supernova neutrinos. The excellent background discrimination potential makes it even possible to search for neutrinoless $\beta\beta$ decay by loading several tons of a candidate isotope into the detector, in a self-contained inner volume.
The Jiangmen Underground Neutrino Observatory (JUNO) is a next-generation liquid scintillator reactor neutrino experiment being built in the Guangdong province in China. JUNO is a multi-purpose experiment with a wide range of applications in neutrino physics, ranging from a mass-ordering determination to solar, geo, and atmospheric neutrino measurements, to detecting supernovae. Moreover JUNO will measure oscillation parameters with a precision of less than one percent. The over 50-meter wide experimental hall, which was recently successfully dug out, stands under more than 700 m of granite overburden. It contains a 35.4-meter diameter acrylic vessel containing 20 ktonne of LAB-based liquid scintillator, making it the largest liquid scintillator container in the world. The spherical detector is submerged in a water pool shielding doubling as a water cherenkov detector which, along with a top tracker above it, serves to precisely reconstruct and veto muon events. Surrounding the vessel are 17612 20'' PMTs and 25600 3'' PMTs, optimised towards JUNO's main goal: a 3-4 sigma significance on the neutrino mass-ordering within the first six years of data-taking, which is expected to start in 2022. This talk presents the detector design and status of JUNO.
In this talk I will discuss the calculation of neutrino oscillations in the early Universe and of the neutrino thermalization, quantified in particular by the effective number of neutrinos (Neff). Precision calculations of Neff are important in light of the future improvements in the experimental determinations. I will briefly review the state-of-art numerical results and discuss the theoretical expectations for Neff in different scenarios: the standard three-neutrinos case, a case with an additional light sterile neutrino and a non-standard scenario with low-reheating.
Neutrino oscillations in the early Universe are commonly assumed to preserve homogeneity and isotropy. However, we know that collective oscillations can break both in the environments of supernovae and neutron star mergers. In this talk I will describe the conditions under which homogeneity and isotropy are broken by neutrino oscillations in the early Universe, and I will demonstrate how this materializes during standard neutrino decoupling with a simple model. Finally, I will comment on the possible observable impact of inhomogeneous and anisotropic neutrino oscillations in the early Universe.
The ESA Euclid mission will map the cosmic web with unprecedented precision. Among the main scientific objectives of Euclid one stands out for its interdisciplinary impact: the measurement of the sum of neutrino masses.
In this talk I will highlight the challenges that cosmology will have to face in order to exploit the accuracy of Euclid data, and achieve this groundbreaking result. I will also show the potential consequences of such measurement on the neutrino mass ordering.
The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double-beta (0νββ) decay that has been able to reach the one-ton scale. The detector, located at the Laboratori Nazionali del Gran Sasso in Italy, consists of an array of 988 TeO2 crystals arranged in a compact cylindrical structure of 19 towers. Following the completion of the detector construction in August 2016, CUORE began its first physics data run in 2017 at a base temperature of about 10 mK. Following multiple optimization campaigns in 2018, CUORE is currently in stable operating mode. In 2019, CUORE released its 2nd result of the search for 0νββ corresponding to a TeO2 exposure of 372.5 kg∙yr and a median exclusion sensitivity to a 130Te 0νββ decay half-life of 1.7 × 10^25 yr. We find no evidence for 0νββ decay and set a 90% C.L. Bayesian lower limit of 3.2 × 10^25 yr on the 130Te 0νββ decay half-life. In this talk, we present the current status of CUORE's search for 0νββ, as well as review the detector performance. We finally give an update of the CUORE background model and the measurement of the 130Te two neutrino double-beta (2νββ) decay half-life.
KamLAND-Zen 800 is a neutrinoless double-beta decay search experiment with the Kamioka Liquid-scintillator Anti-electron Neutrino Detector (KamLAND). In 2019, we started KamLAND-Zen 800 experiment with 745 kg of xenon. We achieved the background reductions by reducing the radioactive materials in the newly fabricated 25-μm-thick nylon film container for the Xe-loaded LS and developing a new analysis technique to reject the cosmic-ray muon spallation backgrounds. We continue the observation to search within the inverse hierarchy region of the Majorana neutrino effective mass.
In the presentation, the detector status and the estimation of the 0nbb decay search backgrounds will be reported.
NEXT is a staged experimental program aiming at the detection of neutrinoless double beta (ββ0ν) decay in 136Xe using successive generations of high-pressure gaseous xenon time projection chambers. The collaboration is presently concluding four years of operation of NEXT-White, a radiopure 50-cm diameter and length TPC operated with enriched xenon at 10 bar, at the Laboratorio Subterràneo de Canfranc. NEXT-White has successfully demonstrated the two key features of the technology, namely excellent energy resolution (1% FWHM at the Q-value of the decay) and highly effective topological-based background discrimination. The latter was recently boosted using a new image deblurring technique which allows reducing background by an additional factor of ~5 compared to the previous state-of-the-art. This technique is presently employed for the analysis of two-neutrino double beta decay events recorded in NEXT-White. The next stage of the program is NEXT-100, planned for commissioning in 2021, which will be twice larger than NEXT-White, and operated with 97 kg of enriched xenon at 15 bar, with half-life sensitivity on the scale of 1026 y. In parallel, the collaboration pursues an extensive R&D program to develop the capability of detecting the 136Ba daughter resulting in 136Xe double beta decays inside a running TPC using single molecule fluorescence imaging. This effort can lead to a background-free search for ββ0ν decay on the tonne-scale, with half-life sensitivities close to 1028 y. This talk will present the current status of the program, focusing on recent developments in topological analysis and barium tagging, and outline the future steps of the experiment.
Neutrinoless double beta decay (0νββ) is a hypothetical lepton number violating nuclear process which creates matter without a compensation of anti-matter. If observed, it would give an insight on why our universe is predominantly composed of matter. Furthermore, it would reveal the Majorana nature of neutrinos, namely that they are equal to their anti-matter counterpart, and possibly explain why their mass is so small.
Since 2011, the GERDA collaboration has searched for 0νββ of $^{76}$Ge by operating bare germanium detectors, enriched in the double-beta decaying isotope $^{76}$Ge, in liquid argon. Exploiting the combination of excellent energy resolution of germanium and scintillating properties of argon, the GERDA experiment succeeded to perform a background-free search of 0νββ for the entire duration of its Phase II.
In November 2019, after fulfilling and exceeding the design goals of the experiment, data taking was stopped. No signal has been observed, hence a lower limit on the half-life of 0νββ in $^{76}$Ge has been set at $T_{1/2}>1.8 \times 10^{26}$ years at 90% C.L..
At this talk the final results of the GERDA experiment will be presented.
Super-Kamiokande (SK) is a 50-kton water Cherenkov detector, instrumented with ∼13k photomultipliers and running since 1996. It is sensitive to neutrinos with energies ranging from 4.5 MeV to several TeV. A new framework has been developed for the follow-up of gravitational wave (GW) alerts issues by the LIGO-Virgo collaboration (LVC). Neutrinos are searched for, using a 1000-second time window centred on the alert time and in both SK low-energy and high-energy samples.
Such observation can then be used to constrain the neutrino emission from the GW source. The significance of potential signals has been obtained by comparing neutrino direction with the localisation of the GW. The computation of limits on incoming neutrino flux and on the total energy emitted in neutrinos by the source has been performed for the different neutrino flavours.
The results using the LVC GWTC-2 catalogue (covering O3a period) will be presented, as well as the plans for future real-time public release of follow-ups for O4 period (in 2022) and beyond.
The last decade of experimental data has provided many insights on the
most extreme phenomena in the Universe where gravity and particle
physics come together. A multi-messenger approach, combining data from
complementary experiments and exploiting the intimate connection
between ultra-high-energy cosmic rays, photons and neutrinos, is
needed to shed light on the still open crucial aspects regarding their
sources and propagation to the Earth. The Pierre Auger Observatory,
the largest ultra-high-energy cosmic ray observatory ever built, has a
high potential for multi-messenger studies given its sensitivity to
photons and neutrinos in the EeV energy range and above. We report
results and perspectives for both diffuse and targeted searches.
The Surface Detector (SD) of the Pierre Auger Observatory is used to search for ultra-high-energy (UHE) neutrinos with energies beyond 0.1 EeV of all flavours. They induce extensive air showers (EASs) that are efficiently detected and well distinguishable from those produced by UHE cosmic rays. This, along with the large aperture of the SD, leads to a UHE neutrino sensitivity competitive to that of dedicated neutrino telescopes. No UHE neutrinos have been found to date, imposing strong limits on their flux and thereby severely constraining a variety of production models. Stringent limits on the UHE neutrino flux from point sources in a large declination band (−80° to 60°) are obtained. The varying exposure for different EAS inclinations, moving across the sky, temporarily causes a strongly enhanced neutrino sensitivity in certain directions, benefiting multi-messenger follow-up searches of transient events. As an application, the efforts of gravitational wave event follow-up searches for UHE neutrinos will be discussed.
In the constrained sequential dominance (CSD), tri-bimaximal mixing (TBM) pattern of the neutrino sector has been explained, by proposing a certain Yukawa coupling structure for the right-handed neutrinos of the model. However, from the current experimental data it is known that the values of the neutrino mixing angles are deviated from the TBM values. In order to explain this neutrino mixing, we first propose a phenomenological model where we consider Yukawa couplings which are modified from that of CSD. Essentially, we add small complex parameters to the Yukawa couplings of CSD. Using these modified Yukawa couplings, we demonstrate that neutrino mixing angles can deviate from their TBM values. We also construct a model, based on a flavor symmetry, in order to justify the modified form of Yukawa couplings of our work.
We perform a thermal unflavored leptogenesis analysis on minimal left-right symmetric models in which the left-right symmetry is identified as generalized parity or charged conjugation. When left-right symmetry is unbroken in lepton Yukawa sector, the neutrino Dirac coupling matrix is completely determined by neutrino masses and mixing angles, which allows CP violation needed to generate leptogenesis totally reside in the low energy sector.
Both type I and mixed type I + II neutrino mass generation mechanisms, together with two lepton asymmetry generation ones, are considered. After solving the Boltzmann equations numerically, we find that the low energy CP phases in the lepton mixing matrix can successfully produce the observed baryon asymmetry, and in some cases the Dirac CP phase can be the only source of CP violation. Finally we discuss the interplay among low energy CP phase measurements, leptogenesis and neutrinoless double beta decay, and show that the viable models for successful leptogenesis can be probed in next generation neutrinoless double-beta decay experiments.
The ANITA experiment has registered two anomalous events that can be interpreted as $\nu_\tau$ or $\bar{\nu}_\tau$ with a very high energy of O(0.6)~EeV emerging from deep inside the Earth. At such high energies, the Earth is opaque to neutrinos so the emergence of these neutrinos at such large zenith angles is a mystery. I will present a model that explains the two anomalous events through a $L_e-L_\tau$ gauge interaction involving two new Weyl fermions charged under the new gauge symmetry. We find that, as a bonus of the model, the lighter Weyl fermion can be a dark matter component. We discuss how the ANITA observation can be reconciled with the IceCube and Auger upper bounds. We also demonstrate how this model can be tested in future by collider experiments.
The constraints on invisible neutrino decay can come from future planned/proposed long baseline experiments - T2HK/T2HKK and ESS$\nu$SB. The T2HKK and ESS$\nu$SB experiments are both designed to have energy peak near the second-oscillation maximum of $P_{\mu e}$ while T2HK has the energy peak at the first oscillation maximum of $P_{\mu e}$. We perform a full three flavour study using matter effect and obtain the sensitivity to $\tau_3 / m_3$ for these experiments. In particular, we investigate how the experiments at first and second oscillation maximum fare in presence of neutrino decay. We also study the important factors on which the measurement of $\theta_{23}$ can depend in presence of decay. We have found that in presence of decay, the overall octant sensitivity is enhanced. This can be attributed to the octant sensitive contribution coming from the disappearance channel ($P_{\mu \mu}$) in presence of decay.
Double beta decay is predicted in the Standard Model with the emission of two active neutrinos. Models in which light exotic fermions are emitted, replacing one or both the neutrinos in the final state, could be tested through the search for spectral distortions in the electron spectrum with respect to the Standard Model expectations. In this contribution the discovery potential of a selection of neutrinoless double beta decay experiments will be presented, under two concrete scenarios: the single production of a light sterile neutrino in double beta decay and the pair production of light Z$_2$-odd fermions. It will be shown that future searches allow to test for the first time a new part of the parameter space at the MeV-mass scale, as discussed in [1].
[1] M. Agostini, E. Bossio, A. Ibarra, X. Marcano, arXiv:2012.09281 (2020)
It has been recently shown that the identification of the single positively-charged ion Ba2+ produced in double beta decay events in Xe-136 may be possible in a high-pressure gas TPC using molecular indicators. The NEXT collaboration is pursuing an intense R&D program geared towards a future detector able to detect “tag” the Ba2+ produced in such events, a technique that could lead to an essentially background-free neutrinoless double beta decay experiment. In this talk, I will describe the R&D program of the NEXT collaboration. Particular emphasis will be given to the BOLD program, based on a new type of fluorescent bicolor indicators (FBI) capable of separating chelated indicators following Ba2+ capture from unchelated ones, with a very large signal to noise ratio.
The development of cryogenic calorimeters to search for neutrinoless double-beta decay (0$\nu$DBD) has given in the last years increasingly promising results. The possibility of achieving ton-scale exposures, maintaining an excellent energy-resolution, makes this kind of detector very suitable for a next-generation experiment.
In order to achieve a nearly background-free condition, scintillating crystals for 0$\nu$DBD have been developed. Thanks to the light-assisted particle discrimination, cryogenic calorimeters based on scintillating crystals demonstrated the complete rejection of the dominant alpha background.
The CUPID-0 detector, an array of 24 ZnSe enriched crystals, is one of the most advanced examples of such experimental technique.
CUPID-0 has taken data at LNGS from 2017 to 2019, measuring the lowest counting rate in the region of interest for this technique. It has also set the most stringent limit on the Se-82 0$\nu$DBD, reaching competitive results with limited exposure of approximately 10 kg $\cdot$ y. In this contribution, we present the final results of CUPID-0 Phase I including a detailed model of the background, the measurement of the Se-82 2$\nu$DBD half-life, and the search for CPT violation.
Furthermore, we present the first results after the detector upgrade in 2019 which purpose is a better understanding of the background sources.
The search for $0 \nu EC \beta^+$ of $^{120}$Te with CUORE
Alice Campani (on behalf of the CUORE collaboration)
Università degli studi di Genova – INFN
CUORE (Cryogenic Underground Observatory for Rare Events) is a ton-scale experiment located at the LNGS searching for neutrinoless double beta decay of $^{130}$Te. The detector consists of TeO$_2$ crystals operated as cryogenic calorimeters. The use of tellurium with natural isotopic composition allows us to search for the decay of other isotopes. The neutrinoless positron emitting electron capture of $^{120}$Te (natural abundance 0.09(1)%) has a clear signature from the 511-keV annihilation γ rays. We present an analysis of this process based on a new algorithm to perform the simultaneous spectral fit over five selected decay scenarios. Each scenario is characterized by a set of crystals simultaneously interested by a detectable energy release. We describe the blinded analysis we performed to model multi-site background structures and study the systematics.
The next generation experiment CUPID will search for neutrinoless double beta decay using scintillating Li$_2$MoO$_4$ bolometers to study the candidate isotope $^{100}$Mo. The scintillating properties of these crystals allow for the dual read-out of heat and light signals to suppress the background induced by alpha particles. This feature, together with the high Q-value of $^{100}$Mo, will reduce the background level by a factor 100 with respect to CUORE, the predecessor of CUPID. The R&D results presented concern the study of the detector performances in terms of energy resolution, a key element to search for rare decays, and light yield, to understand the particle identification capabilities of the experiment.
I present dedicated studies and measurements aiming to the reduction of the $\gamma$ background in the $0\nu\beta\beta$ ROI for TeO$_{2}$ calorimeters. This is mainly due to 2615 keV $\gamma$'s scattering Compton with materials next to the detectors. It can be lowered by replacing the usual copper holders with organic compounds structures. TeO$_{2}$ crystals, positioned in a PMMA holder, have been characterized. In particular, they have an energy resolution of $\sim$ 5 keV at 2615 keV, the same of a copper holder, built as reference. The PMMA assembly ROI background is lower than the one in copper. A more realistic application has been considered by simulating the inner CUORE detector supporting structure made of PMMA. I obtain a considerable $\gamma$ background reduction factor of $4.7^{+0.5}_{-0.6}$ for photons coming from environmental sources and of $5.0^{+0.1}_{-0.2}$ for near detector contaminations.
Project 8 is a next-generation direct neutrino mass experiment using tritium beta decay. To reach the target sensitivity of 40meV, major technological development is necessary. Building up on the milestones achieved so far, I will present the next developmental phases of Project 8: In Phase III, atomic tritium will be trapped magnetically, and cyclotron radiation emission spectroscopy (CRES) will be demonstrated in free space. The knowledge gained from Phase III will inform the design and operation of a large-volume atomic tritium experiment, sensitive to the entire mass range allowed by the inverse neutrino mass hierarchy.
In this talk, I will briefly describe the technique we developed to study the pile-up rejection capability of cryogenic bolometers. The precise characterization of the detector time resolution is indeed of crucial importance for next-generation cryogenic-bolometer experiments searching for neutrinoless double-beta decay, such as CUPID, in order to discriminate against the pile-up of two-neutrino double decay events, which will represent a non-negligible contribution to the background. Our approach consists in producing artificial pile-up events with a programmable waveform generator, thus allowing for a complete control of the time separation and relative energy of the individual components of the generated pile-up events. I will present the results we obtained by applying this technique to a small array of detectors at the Laboratori Nazionali del Gran Sasso, in Italy.
The search for neutrinoless double beta decay could cast light on one critical piece missing in our knowledge i.e. the nature of the neutrino mass. Its observation is indeed the most sensitive experimental way to prove that neutrino is a Majorana particle. The observation of such a potentially rare process demands a detector with an excellent energy resolution, an extremely low radioactivity and a large mass of emitter isotope. Nowadays many techniques are pursued but none of them meets all the requirements at the same time. The goal of R2D2 is to prove that a spherical high pressure TPC could meet all the requirements and provide an ideal detector for the 0νββ decay search. The prototype has demonstrated an excellent resolution with Argon and the preliminary results with Xenon are already very promising. In the proposed talk the R2D2 results obtained with the first prototype will be discussed as well as the project roadmap and future developments.
The ANTARES neutrino telescope and its next-generation successor, KM3NeT, located in the abyss of the Mediterranean Sea, have been designed to study neutrinos from a variety of sources over a wide range of energies and baselines. One of the primary goals of the experiments is to determine the Earth matter effects stemming from the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range.
In this talk, I will present the physics potential of ANTARES and KM3NeT/ORCA (ORCA being the low energy sub-array of KM3NeT) detectors to measure sub-dominant effects in the atmospheric neutrino oscillations, namely, neutrino non-standard interactions (NSIs). A likelihood-based search for NSIs with 10 years of atmospheric muon-neutrino data recorded with ANTARES will be reported and sensitivity projections for ORCA, based on realistic detector simulations, will be shown. Remarkably, the limits obtained with ANTARES in the NSI $\mu - \tau$ sector represent the most stringent bounds up to date.
Addressing the origin of the observed astrophysical neutrino flux is of paramount importance nowadays, since the sources generating such neutrinos still remain a mystery. Among the likely astrophysical sources of detectable high-energy neutrinos (e.g. blazars, supernova remnants etc.), also Gamma-Ray Bursts (GRBs) play a fundamental role, since they are among the few astrophysical sources capable of achieving the required energy to contribute to the detected
astrophysical neutrino flux. Within this context, we present the results of a stacked search for muon astrophysical neutrinos performed in coincidence with 784 GRBs in the period 2007-2017 using ANTARES data. The major improvement with respect to previous analyses is now the estimation of systematic uncertainties due to poor knowledge on some of the model parameters were computed on the diffuse flux, propagating the uncertainties on the barely characterized GRB parameters of each individual burst to the stacked limit. Given the absence of coincident neutrinos with the analyzed GRBs, this analysis has allowed to constrain the contribution of the detected GRB population to the neutrino diffuse flux to be less than 10% around 100 TeV.
In a recent time-integrated investigation of a catalog of 110 gamma-ray emitters, IceCube observed a cumulative neutrino excess in the flux produced during 10 years. Such an excess, incompatible with the background at the level of $3.3\sigma$, was mainly due to the starburst galaxy NCG 1068 and the BL Lacs TXS 0506+056, PKS 1424+240 and GB6 J1542+6129. Here we present the results of a time-dependent analysis of the same catalog. Unlike for past searches, this analysis does not only look for the most significant cluster of events but it can potentially detect multiple flares from a single direction. This analysis confirms a significant neutrino excess in the northern sky and identifies M87, hosting a very close-by black hole, as the most significant time-dependent source of the catalog. Moreover, it confirms the detection of a long flare in 2014/2015 and finds a shorter second flare, related to the time of the high-energy neutrino event in 2017, from the direction of TXS 0506+056.
Blazars are the most extreme subclass of active galactic nuclei with relativistic jets emerging from a super-massive black hole and forming a small angle with respect to our line of sight. Blazars are also known to be flaring sources: they exhibit large flux variations over a wide range in frequency and on multiple timescales, ranging from a few minutes to several months. Blazar flares have been suggested as ideal candidates for enhanced neutrino production. Interestingly, the flaring blazar TXS 0506+056 was the first astrophysical source to be associated with a high-energy neutrino. While neutrino production during gamma-ray flares has been widely discussed, the neutrino yield of X-ray flares has received less attention. Here, we compute the predicted neutrino fluence of X-ray flares detected in blazars observed with Swift-XRT more than 50 times. To this end, we applied the Bayesian Block algorithm to the 1 keV XRT light curves of frequently observed blazars to characterize statistically significant variations, at the same time suppressing the inevitable contaminating observational errors. We categorized flares into classes based on their variation from the time-average value of the data points. Using spectral information, we computed for each flare the 1-10 keV fluence. The latter is shown to be a good proxy for the all-flavor neutrino flux in the scenario where X-ray flares are powered by synchrotron radiation of protons intermittently accelerated in the blazar jet. We present preliminary results of our analysis for a few indicative blazars.
https://mediaspace.unipd.it/media/XIX+International+Workshop+on+Neutrino+Telescopes+- +Parallel+Room+2/1_5ximyxtb?st=7150&ed=7268
Dark matter's existence (DM) has been well-established by repeated experiments over many length scales. Even though DM is expected to make up 85% of the current matter content of the Universe, its nature remains unknown. One broad class of corpuscular DM motivated by Standard Model (SM) extensions is weakly interacting massive particles (WIMPs). WIMPs generically have a non-zero cross-section with SM nuclei, so they can scatter off nuclei in large celestial bodies such as the Sun, thereby losing energy and becoming gravitationally bound. After repeated scatterings, WIMPs sink to the solar center, leading to an excess of WIMPs there. Furthermore, WIMPs can annihilate to unstable SM particles, eventually yielding stable SM particles. Only neutrinos can escape the dense solar core. Thus, neutrino observatories may look for these neutrinos as evidence of WIMPs. In this talk, I will present the current status of IceCube's solar WIMP search, which covers the mass range from 10 GeV to 1 TeV.
In this controbution a combined measurement of the energy spectra of atmospheric electron and muon neutrinos in the energy range between 100 GeV and 50 TeV with the ANTARES neutrino telescope is presented. The analysis uses 3012 days of detector livetime in the period 2007–2017, and selects 1016 neutrinos interacting in (or close to) the instrumented volume of the detector, yielding shower-like events and starting track events. The contamination of the atmospheric muon background in the final sample is suppressed at the level of a few per mill by different steps in the event selection, including a Boosted Decision Tree classifier. The distribution of reconstructed events is unfolded in terms of electron and muon neutrino fluxes. The derived energy spectra are compared with previous measurements.
The discovery of an astrophysical flux of high-energy neutrinos with IceCube is a milestone in the field of multi-messenger astronomy. Traditional time-integrated searches for point-like neutrino sources have so far been unsuccessful because of large backgrounds and weak neutrino signals. IceCube’s capability of observing the sky with full duty cycle enables us to search for transient neutrino emissions and alert the astrophysical community with low latency in case of detection, aiming for the identification of an electromagnetic counterpart of rapidly fading sources. In this talk, the Gamma-Ray Follow Up (GFU) platform will be presented, which allows generating and sending alerts to the astrophysical community in response to the real-time identification of muon neutrino candidates. These alerts are triggered by neutrino clusters coming from, both, catalogued gamma-ray emitters and anywhere in the sky, as well as by single high-energy neutrino events.
Astrophysical neutrinos at hundreds of TeV are expected to originate in
hadronic interactions, but their sources are still unknown. The chance of
identifying the emitting objects can be improved by a rapid electromagnetic
follow-up of neutrino events. Here, the MAGIC telescopes play a relevant role in
identifying very high energy (>100 GeV) γ-ray counterparts. This is achieved by
responding to different types of neutrino alerts issued by the IceCube alert
system. Thanks to this program, a very high energy neutrino detected by
IceCube was found to be spatially coincident with the blazar TXS 0506+056
and in time coincidence with a flare of this source. This is so far the only
observation with a chance coincidence probability rejected at the 3σ level,
suggesting blazars as candidate neutrino emitters.
In this talk a description of MAGIC observation strategy in response to IceCube
alerts will be given, together with a discussion on past follow-up, in particular
on the case of TXS 0506+056.
https://mediaspace.unipd.it/media/XIX+International+Workshop+on+Neutrino+Telescopes+- +Parallel+Room+2/1_5ximyxtb?st=8677&ed=8900
We use perturbation theory to obtain neutrino oscillation probabilities, including the standard mass-mixing paradigm and non-standard neutrino interactions (NSI). The perturbation is made on the standard parameters ${\Delta}{m}_{21}^{2}/{\Delta}{m}_{31}^{2}$ and sin2(θ13) and on the non-diagonal NSI parameters, but keeps diagonal NSI parameters non-perturbated. We perform the calculation for the channels νμ → νe and νμ → νμ. The resulting oscillation formulas are compact and present functional structure similar to the standard oscillation (SO) case. They apply to a wide range in the allowed NSI space of parameters and include the previous results from perturbative approaches as limit cases. Also, we use the compact formulas we found to explain the origin of the degeneracies in the neutrino probabilities in terms of the invariance of amplitude and phase of oscillations. Then we determine analytically the multiple sets of combinations of SO and NSI parameters that result in oscillation probabilities identical to the SO case.
The evolution of effective neutrino masses and mixing parameters in the ordinary matter can be characterized by a complete set of differential equations with respect to the matter parameter $a \equiv 2\sqrt{2}G^{}_{\rm F}N^{}_eE$, in analogy with the renormalization-group equations (RGEs) for running parameters. With some reasonable approximations, we find analytical solutions to the above differential equations, and obtain simple and compact formulas of all the effective oscillation parameters. Interestingly, the ratio of effective Jarlskog invariant $\widetilde{\cal J}$ in matter to its counterpart ${\cal J}$ in vacuum can be well described by $\widetilde{\cal J}/{\cal J} \approx 1/(\widehat{C}^{}_{12} \widehat{C}^{}_{13})$, where $\widehat{C}^{}_{12} \equiv \sqrt{1 - 2 \widehat{A}^{}_* \cos 2\theta^{}_{12} + \widehat{A}^2_*}$ with $\widehat{A}^{}_* \equiv a\cos^2 \theta^{}_{13}/\Delta^{}_{21}$ and $\widehat{C}^{}_{13} \equiv \sqrt{1 - 2 A^{}_{\rm c} \cos 2\theta^{}_{13} + A^2_{\rm c}}$ with $A^{}_{\rm c} \equiv a/\Delta^{}_{\rm c}$.
In this work, we investigate the effects of non-unitary neutrino mixing on the determination of current unknown parameters in neutrino oscillation physics. From our analysis, we found that non-unitarity parameters in the 21 sector are sensitive to the NOνA experiment. However, it is observed that the NOνA experiment is not expected to improve the current knowledge of those parameters. We also found that the sensitivities to current unknowns have deteriorated significantly in the presence of non-unitary lepton mixing and these sensitivities crucially depend upon the new CP-violating phase in the non-unitary mixing. Further, we find that the degeneracy resolution capability of the NOνA experiment is reduced in the presence of non-unitarity parameters. However, the synergy between the currently running experiments T2K and NOνA can improve the parameter degeneracy resolution, and hence there is an enhancement in the sensitivities of unknowns.
Two and three flavor oscillating neutrinos are shown to exhibit the properties bipartite and tripartite quantum entanglement [1]. Neutrino eigenstates are mapped to qubits used in quantum information theory. Such quantum bits of the neutrino state can be encoded on a IBMQ computer using quantum computing as a tool. We show the implementation of entanglement in the two neutrino system (in vacuum) on the IBM quantum processor [2]. Quantum simulation of entangled oscillating neutrinos in matter with non-standard interactions (NSIs) quantum circuits on IBM quantum computer is in progress.
References:
[1]. A.K.Jha, S.Mukherjee and B.A.Bambah, Tri-Partite entanglement in Neutrino Oscillations, [arXiv:2004.14853 [hep-ph]]. (This paper was accepted on 5th January, 2021 for the publications in the journal Modern Physics Letter A).
[2] A.K.Jha, A.Chatla and B.A.Bambah, Quantum simulation of oscillating neutrinos, [arXiv:2010.06458 [hep-ph]].
We explore the role of matter effect in the evolution of neutrino oscillation parameters in the presence of non-standard interactions (NSIs). We derive approximate analytical expressions showing evolution of mass-mixing parameters in matter and in presence of NSIs. We observe that only the NSIs in (2,3) block ($\varepsilon_{\mu\mu}$, $\varepsilon_{\tau\tau}$, and $\varepsilon_{\mu\tau}$) affect the running of $\theta_{23}$. $\varepsilon_{e\mu}$ and $\varepsilon_{e\tau}$ have stronger impact on the $\theta_{13}$ evolution. We show the utility of our approach in addressing some important features related to neutrino oscillation: a) unraveling interesting degeneracies between $\theta_{23}$ and NSI parameters, b) estimating the resonance energy in presence of NSIs when $\theta_{13}$ in matter becomes maximal, c) estimating the required baseline length and neutrino energies to have maximal matter effect in $\nu_{\mu}$ $\rightarrow$ $\nu_{e}$ transition in presence of NSI parameters, and d) studying the impact of NSIs in (2,3) block on the $\nu_{\mu}$ $\to$ $\nu_{\mu}$ survival probability.
We propose a new approach to explore the neutral-current non-standard neutrino interactions (NSI) in atmospheric neutrino experiments using oscillation dips and valleys in reconstructed muon observables, at a detector like ICAL that can identify the muon charge. We focus on the flavor-changing NSI parameter $\varepsilon_{\mu\tau}$, which has the maximum impact on the muon survival probability in these experiments. We show that non-zero $\varepsilon_{\mu\tau}$ shifts the oscillation dip locations in $L/E$ distributions of the up/down event ratios of reconstructed $\mu^-$ and $\mu^+$ in opposite directions. We introduce a new variable $\Delta d$ representing the difference of dip locations in $\mu^-$ and $\mu^+$, which is sensitive to the magnitude as well as the sign of $\varepsilon_{\mu\tau}$, and is independent of the value of $\Delta m^2_{32}$. We further note that the oscillation valley in the ($E$, $\cos \theta$) plane of the reconstructed muon observables bends in the presence of NSI, its curvature having opposite signs for $\mu^-$ and $\mu^+$. We demonstrate the identification of NSI with this curvature, which is feasible for detectors like ICAL having excellent muon energy and direction resolutions. We illustrate how the measurement of contrast in the curvatures of valleys in $\mu^-$ and $\mu^+$ can be used to estimate $\varepsilon_{\mu\tau}$. Using these proposed oscillation dip and valley measurements, the achievable precision on $|\varepsilon_{\mu\tau}|$ at 90% C.L. is about 2% with 500 kt$\cdot$yr exposure. The effects of statistical fluctuations, systematic errors, and uncertainties in oscillation parameters have been incorporated using multiple sets of simulated data. Our method would provide a direct and robust measurement of $\varepsilon_{\mu\tau}$ in the multi-GeV energy range.
We introduce a renormalizable and anomaly-free $U(1)^\prime$ gauge extension of the standard model, and show that it can provide a consistent explanation of a number of prominent low energy anomalies. We show that the simultaneous presence of all portal connections between a neutral dark sector and the SM lead to unique phenomenological signatures at experiment. We further discuss these signatures and the ongoing effort to search for these classes of models, in particular, as a solution to the MiniBooNE low energy excess.
The neutrino experiments that in the near future are expected to shed some light on a series of open fundamental questions (like the final proof of the leptonic CP violation and the determination of its value, the \theta_23 octant determination, the solution of the mass ordering problem) will also reinforce our knowledge of the general neutrino properties and they could be used to search for possible deviations from the expected oscillation and mass pattern. These signals could be indications of new physics and/or of some exotic effects already postulated by theory. In this talk we will focus our attention on two different possible sectors of analysis: the searches for Lorentz Invariance Violation (LIV) and for Non Standard Neutrino Interactions (NSI).
The LIV effects (that could be also interpreted as “low energy” phenomenological manifestations of very high energy quantum gravity theories) could in principle affect the oscillation probability with deviations from the standard scenario, that can be investigated in experiments studying high energy atmospheric and cosmic neutrinos. We will discuss this possibility with particular attention to the search for isotropic effects predicted by models like the HMSR model, on which we have been working.
Concerning the NSI effects, they can be investigated mainly in solar neutrino physics, with particular attention to the ^7Be and even more to the ^8B part of the spectrum, looking for possible deviations from the traditional MSW scenario especially in the vacuum to matter transition region. The search for these signals can be conducted by experiments with high masses and good energy resolution, to guarantee high statistics and a detailed study of the spectrum. Important synergies could come also from the combined analysis of the solar neutrino and the reactor antineutrino signals.
The Large Enriched Germanium Experiment for Neutrinoless $\beta\beta$ Decay (LEGEND) program is a search for the neutrinoless double-beta decay of the $^{76}$Ge isotope. Its first phase, LEGEND-200, uses 200-kg of enriched high-purity germanium (HPGe) detectors in an active liquid argon shield and is currently under construction at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. It has a background index goal of $< 0.6$ counts/ (FWHM t yr), which yields a $3 \sigma$ discovery half-life sensitivity of beyond $10^{27}$ years with a 1 ton-year exposure. LEGEND-1000 is a proposed tonne-scale upgrade with 1000-kg of enriched HPGE detectors that will follow LEGEND-200. It will have a discovery sensitivity beyond $10^{28}$ years. This talk will provide a status update of LEGEND-200 and a review of the proposed LEGEND-1000. Other BSM searches possible in LEGEND are also briefly discussed.
The Majorana Demonstrator is searching for neutrinoless double beta decay ($0\nu\beta\beta$) in $^{76}$Ge, a beyond the standard model second order nuclear process whose discovery would indicate that the neutrino is a Majorana fermion. The experiment consists of a modular array of 44 kg of p-type point contact (PPC) high-purity germanium detectors (HPGe), 30 kg of which are enriched to 88% in $^{76}$Ge. The Demonstrator is constructed from low-background materials and housed at the Sanford Underground Research Facility (SURF). Due to the PPC detector geometry, pulse shape analysis (PSA) cuts can reject many background events. In addition, the experiment has achieved a leading energy resolution of 2.5 keV FWHM at 2039 keV. With 26 kg-yr of exposure, the Majorana Demonstrator has achieved a half-life limit of $>2.7\times10^{25}$ yr at 90% CL. Recently, the experiment has undergone hardware upgrades, including the exchange of several PPC detectors for 4 Inverted Coaxial Point Contact (ICPC) detectors (6.7 kg) which will be used in future experiments. Many PSA routines have also been improved to improve efficiency, uniformity and stability. Many of the detectors, technology and analysis techniques developed by Majorana are being incorporated into LEGEND-200, the first phase of a next-generation search for $0\nu\beta\beta$ in $^{76}$Ge. This talk will present the current status and recent results of the Majorana Demonstrator.
The search for neutrinoless double beta decay (NDBD) provides the most sensitive experimental test of lepton number conservation, as well as a powerful experimental probe of the nature and mass scale of the neutrino. In this talk, I will introduce the nEXO experiment: a proposed next-generation search for the neutrinoless double beta decay of $^{136}$Xe with a halflife sensitivity of ~$10^{28}$ years, two orders of magnitude beyond existing experiments. Building on techniques developed for the successful EXO-200 experiment, the primary detector will be a five-tonne, monolithic liquid xenon time projection chamber (TPC) with a source enriched to 90% in $^{136}$Xe. We will discuss the science goals of nEXO, then describe how the experiment addresses the stringent low-background requirements of next-generation NDBD searches using a combination of conservative design choices (driven by EXO-200 experience) and novel readout schemes designed to improve the energy resolution and background rejection capabilities of the detector.
Project 8 is a tritium endpoint neutrino mass experiment utilizing a phased program to achieve sensitivity to the range of neutrino masses allowed by the inverted mass ordering. The Cyclotron Radiation Emission Spectroscopy (CRES) technique is employed to measure the differential energy spectrum of relativistic decay electrons with high precision. In Phase II, the CRES technique was extended to make its first continuous spectrum measurement on the tritium endpoint. In this talk, we will highlight recent analysis progress towards the final results of Phase II. We will showcase the critical achievements of CRES in this small-scale apparatus, motivating scaling up the technique towards a next-generation neutrino mass experiment.
The Giant Radio Array for Neutrino Detection (GRAND) is a proposed distributed observatory with a total area of 200,000 km2. This observatory will not only be sensitive to Ultra-High-Energy (UHE) neutrinos, but also to UHE photons and UHE cosmic rays; making it a multi-messenger observatory at the highest energies. In this contribution, the current status of the GRAND project will be discussed, with an emphasis on the design of the antenna, our main detection element. In addition, the layout of the first site of 300 antennas (GRANDProto300), as well as the staged road towards the creation of the full detector and its physics potential will be discussed.
The search for neutrino signals using a surface detector array is a challenging task that requires a very good control of the large background the from cosmic radiation. In this work we propose to use the HAWC observatory, an ~22000 m^2 water Cherenkov detector array located at 4100 m a.s.l., to search for neutrino induced muons produced within the largest volcano in Mexico, located in close vicinity of the detector array. We present preliminary results of the background measured with HAWC and a method designed to disentangle the atmospheric muon background from the neutrino induced signals.
Every time researchers have pushed the energy boundary in particle physics we have found something new about our Universe. Recently, IceCube has demonstrated that Neutrino Telescopes can use neutrinos from the cosmos as excellent tools to continue this exploration. The Pacific Ocean Neutrino Explorer (P-ONE) is a proposed initiative to construct one of the largest neutrino telescopes deep in the northern Pacific Ocean off the coast of British Columbia. To overcome the challenges of a deep-sea installation, we have deployed two prototype mooring lines STRAW and STRAW-b in 2018 and 2020. These provide continuous monitoring of optical water properties at a potential detector site in the Pacific. In this talk I will cover the latest results from these prototype lines and plans to deploy P-ONE off the coast of Vancouver Island.
MicroBooNE is a Liquid Argon Time Projection Chamber detector that has been taking data since 2015. One of its primary goals is to investigate the unexplained excess of electromagnetic events in the lowest energy ranges observed by the MiniBooNE experiment located along the same neutrino beamline. While one leading interpretation of this anomaly is electron neutrino appearance due to sterile neutrino oscillations, a viable alternate interpretation is neutrino-induced single photon events. The MicroBooNE single photon analysis aims to test this interpretation by measuring the rate of neutrino-induced resonant neutral current (NC) delta baryon production and subsequent delta radiative decay with a single photon in the final state, NC Δ→N𝛾. This search for a process that has never been observed before in neutrino scattering is projected to improve upon the current experimental limit from T2K by greater than an order of magnitude. This talk will present the status of the MicroBooNE single photon analysis and the outlook for subsequent measurements.
The liquid argon time projection chamber (LArTPC) is an advanced technology to detect neutrinos with its superb imaging and calorimetry capabilities in a fully active volume. The MicroBooNE detector, which is a single-phase LArTPC of 85-ton active mass located near the Earth's surface, was built to primarily investigate the low energy excess (LEE) of electron neutrino charged-current events and to measure the neutrino-argon scattering cross sections, using the Booster Neutrino Beam (BNB) at Fermilab. The search for LEE is of great scientific interest in the context of the existence of light sterile neutrinos.
In this talk, an end-to-end reconstruction, selection, and analysis chain of electron neutrino charged-current events based on the novel Wire-Cell reconstruction paradigm will be presented. The unique challenges of the large cosmic-ray muon backgrounds at a surface detector and the overwhelming charged-current and neutral-current backgrounds from the beam muon neutrinos are well addressed in this procedure. Validation of this electron neutrino selection using the Neutrinos at the Main Injector Beam (NuMI) will be shown as well.
MicroBooNE is an 85-ton active mass liquid argon time projection chamber (LArTPC) at Fermilab. Its excellent calorimetry and resolution, along with its exposure to two neutrino beamlines make it a powerful detector not just for neutrino physics, but also for Beyond the Standard Model (BSM) physics and astrophysics. The experiment has competitive sensitivity to Heavy Neutral Leptons arising in the leptonic decay modes of kaons, and also to light scalars that can be produced in association with pions. In addition, MicroBooNE serves as a platform for prototyping searches for rare events in the future Deep Underground Neutrino Experiment (DUNE). This talk will explore the capabilities of LArTPCs for BSM physics and astrophysics and highlight some recent results from MicroBooNE.
CUPID is a next-generation tonne-scale bolometric neutrinoless double
beta decay experiment to probe the Majorana nature of neutrinos and
discover Lepton Number Violation if the effective neutrino mass is
greater than 10 meV. CUPID will be built on experience, expertise and
lessons learned in CUORE, and will be installed in the current CUORE
infrastructure in the Gran Sasso underground laboratory. The CUPID
detector technology, successfully tested in the CUPID-Mo experiment, is
based on scintillating bolometers of Li2MoO4 enriched in the isotope of
interest 100Mo. In order to achieve its ambitious science goals, CUPID
aims to reduce the backgrounds in the region of interest by a factor 100
with respect to CUORE. This performance will be achieved by introducing
the high efficiently alpha/beta discrimination demonstrated by the
CUPID-0 and CUPID-Mo experiments, and using a high transition energy
double beta decay nucleus such as 100Mo to minimize the impact of the
gamma background. CUPID will consist of about 1500 hybrid heat-light
detectors for a total isotope mass of 250 kg. The CUPID scientific reach
is supported by a detailed and safe background model that uses CUORE,
CUPID-Mo and CUPID-0 results. The required performance
in terms of energy resolution, alpha rejection factor and crystal purity
have already been demonstrated and will be presented.
The CUPID-Mo experiment is devoted to the search of neutrinoless double beta decay, 2β0ν. This small-scale array of scintillating bolometers has set in 2020 the best limit to the half-live of 2β0ν in 100Mo, with 2.17 kg x y of exposure. CUPID-Mo has demonstrated the maturity of the scintillating bolometric technique for CUPID (Cuore Upgrade with Particle Identification), the next generation 2β0ν ton-scale cryogenic experiment.
CUPID-Mo consists of 20 enriched Li2100MoO4 scintillating crystals, at the Laboratoire Souterrain de Modane (France). The simultaneous measurement of heat and light allows rejecting the α background.
In this talk we will present the data analysis corresponding to a 380 day period acquired between March 2019 and April 2020. This analysis lead to the new limit on 2β0ν in 100Mo of T1/2 > 1.5 x 10^24 yr at 90% CI, corresponding to an effective Majorana mass < (0.31 – 0.54) eV.
I will report on the light sterile neutrino search from the first four-week science run of the KATRIN experiment. Beta-decay electrons from a high-purity gaseous molecular tritium source are analyzed by a high-resolution MAC-E filter down to 40 eV below the endpoint at 18.57 keV. The analysis of the spectral shape of the spectrum near the endpoint leads to an improvement over the previous direct measurement of the neutrino mass, with a new upper limit of 1.1 eV at 90% C.L. Analyzing the shape of the whole spectrum down to 40 eV below the endpoint, we find no significant distortion compared to the standard model expectation. Therefore, exclusion bounds on the sterile mass and mixing are reported. These new limits supersede the Mainz results and improve the Troitsk bound. The reactor and gallium anomalies are further constrained.
The Borexino detector, located at the Laboratori Nazionali del Gran Sasso in Italy, is a liquid scintillator detector with a primary goal to measure solar neutrinos. The sub-dominant $\textrm{CNO}$ cycle in the Sun is assumed to be the main energy production mechanism in heavier stars. The existence of this fusion process in Nature has been recently confirmed by Borexino (5$\sigma$ C.L.) for the first time through the detection of neutrinos from the $\textrm{CNO}$ cycle in the Sun. A direct measurement of this fusion process is challenging due to the high spectral correlation with the detector background $^{210}\textrm{Bi}$ and the solar $pep$ neutrino signal. In order to prove the sensitivity to $\textrm{CNO}$ neutrinos, a dedicated toy Monte Carlo procedure is needed to evaluate the discovery potential applying separate constraints on the $^{210}\textrm{Bi}$ and $pep$ neutrino interaction rates. Here, the Standard Solar Model predictions for low- and high-metallicity are used as inputs for the simulation studies. In the so-called Borexino Phase-III, namely the data-taking period from July 2016 to February 2020, the sensitivity is compatible with the significance observed on data. In this talk, the Borexino sensitivity study to $\textrm{CNO}$ neutrinos is presented.
The Jiangmen Underground Neutrino Observatory (JUNO) features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector. Some of JUNO's features make it an excellent experiment for $^8$B solar neutrino measurements, such as its low-energy threshold, its high energy resolution compared to water Cherenkov detectors, and its much large target mass compared to previous liquid scintillator detectors. In this talk, we present a comprehensive assessment of JUNO's potential for detecting $^8$B solar neutrinos via the neutrino-electron elastic scattering process. A reduced 2 MeV threshold on the recoil electron energy is found to be achievable assuming the intrinsic radioactive background $^{238}U$ and $^{232}Th$ in the liquid scintillator can be controlled to 10$^{-17}$ g/g. With ten years of data taking, about 60,000 signal and 30,000 background events are expected. This large sample will enable an examination of the distortion of the recoil electron spectrum that is dominated by the neutrino flavor transformation in the dense solar matter, which will shed new light on the tension between the measured electron spectra and the predictions of the standard three-flavor neutrino oscillation framework. If $\Delta m^{2}_{21}=4.8\times10^{-5}~(7.5\times10^{-5})$ eV$^{2}$, JUNO can provide evidence of neutrino oscillation in the Earth at the about 3$\sigma$ (2$\sigma$) level by measuring the non-zero signal rate variation with respect to the solar zenith angle. Moveover, JUNO can simultaneously measure $\Delta m^2_{21}$ using $^8$B solar neutrinos to a precision of 20% or better depending on the central value and to sub-percent precision using reactor antineutrinos. A comparison of these two measurements from the same detector will help elucidate the current tension between the value of $\Delta m^2_{21}$ reported by solar neutrino experiments and the KamLAND experiment.
Advances in dark matter detection call for even more massive underground experiments than state-of-the-art. I will illustrate how such experiments can act as unique telescopes for exploring neutrino astronomy. As I will show, using neutrinos, future dark matter experiments could potentially offer new insights into forecast of supernovae as well as the origin of supermassive black holes observed in the centers of nearly all galaxies.
The Super-Kamiokande (SK) experiment is a 50 kton water-Cherenkov detector located in Kamioka, Japan. With its 40% photocoverage, it has been collecting data since 1996 and is responsible for the very first observation of neutrino oscillations through the analysis of atmospheric neutrinos. Nowadays, the atmospheric neutrinos measurements of the SK experiment keeps providing some of the most precise measurements for neutrino oscillation parameters such as θ23, the neutrino mass ordering, Δm^2_32, and, to a lesser extent, the δCP phase.
In this presentation, an overview of the most recent atmospheric neutrino oscillation analysis results will be given, as well as, a glimpse of what is to come, concerning atmospheric neutrinos, in the recently started Gd-doped phase of the detector. This detector upgrade (SuperK-Gd), provides an efficient neutron tagging via Gd-neutron capture, potentially enhancing the sensitivity of the atmospheric neutrino oscillation analysis.
The Jiangmen Undergrond Neutrino Observatory (JUNO) is an upcomming multipurpose experiment focused on resolving the neu- trino mass ordering, an open question of modern neutrino physics. With its 20-kton liquid scintillator target instrumented with 18000 20” PMTs and 25600 3” PMTs the JUNO detector will measure neu- trino spectrum from nuclear reactors at about 53 km distance with 3% energy resolution at 1 MeV. It will allow to resolve the oscillation pattern driven by both the larger mass splittings (∆m231 and ∆m232) and the smaller one (∆m21). This will allow JUNO alone to determine the correct mass ordering at a 3-sigma confidence level within 6 years and provide valuable input for joint analyses with other experiments. Besides that JUNO will measure three oscillation parameters: θ12, ∆m21 and ∆m231 with better than 0.6% accuracy, largerly improving the current precision.
Hyper-Kamiokande is a future experiment in Japan to measure neutrino oscillations with beam and atmospheric neutrinos, to study astrophysical neutrinos, and to search for proton decay. It uses the well-established water Cherenkov detector technique, with improved photosensors and increased fiducial volume, relative to the current generation’s Super-Kamiokande detector. Combined with the upgraded J-PARC neutrino beam, Hyper-Kamiokande will be able to measure neutrino oscillations with an unprecedented precision. Construction has recently commenced, and data taking will begin in 2027. We will present the sensitivity of Hyper-K to CP violation, and other oscillation parameters of interest. These studies are based on the T2K model of systematic uncertainties projected according to the expected precision from the next generation of near and intermediate detectors in the J-PARC neutrino beam.
The T2K experiment is moving towards the T2K-II phase. The plans for T2K-II foresee an increase of the beam power and an upgrade of its near detector ND280 in 2022. The aim is to increase the statistics while reducing at the same time the systematic error from 6% to 4%. This will enable T2K to significantly improve the recently published first measurement of $\delta_{CP}$ which indicates the observation of matter antimatter asymmetry in the leptonic sector.
The ND280 upgrade concept consists on the installation of several new sub-detectors: two time-projection-chambers to measure tracks at high angle (HA-TPCs) and a fully active Super-Fine-Grained-Detector (SuperFGD) both fully surrounded by six time-of-flight (TOF) panels.
The new sub-detectors will not only increase the angular detection efficiency making it more similar to that in the far detector, Super Kamiokande, but will have some features which will allow achieving a deeper understanding of the neutrino interactions. Among other improvements, the upgraded ND280 will have 3D tracking capabilities, improved timing information, lower proton detection threshold and the ability to detect neutrons released in the interaction.
Overall, the upgraded ND280 is expected to significantly boost its current performance. In this talk the motivation, status and physics benefits of the upgraded ND280 detector will be presented.
SoLid is a short baseline neutrino experiment at the BR2 reactor in Mol. It is searching for sterile neutrino oscillations and make precisions measurements of the neutrino energy spectrum from a highly enriched Uranium reactor core. The signature of neutrino reactions due to inverse beta decay is a coincidence of an electromagnetic energy deposition followed by the nuclear capture of a neutron (NS). A significant background to this signature is the BiPo-214 decay (a beta- followed by an alpha-decay). This presentation will discuss different ways to identify and discriminate against this background based on the waveform of the NS. A traditional pulse shape discrimination method yields 80% signal efficiency while rejecting 80% of the background. Additionally, a 1-dimensional convolutional neural network was developed improving the performance by a factor of 3-4. This presentation will introduce the general setup and report on the methods and their performance.
The JSNS2 experiment aims to search for the existence of sterile neutrino at J-PARC. A 1 MW beam of 3 GeV protons incident on a spallation neutron target produces an intense neutrino beam from muon decay at rest. The experiment will search for muon anti-neutrino to electron anti-neutrino oscillations which are detected by the inverse beta decay (IBD) interaction, followed by gammas from neutron capture on Gd. One of the dominant backgrounds of IBD events is fast neutrons induced by cosmic muons. In order to reject the background, the pulse shape discrimination (PSD) method is used to differentiate between neutron and gamma. In JSNS2, 1400L of DIN, 8% of concentration, was dissolved into GdLS in Dec. 2020 to improve the PSD capability. In this talk, we introduce how to use PMT waveforms for PSD, and the waveform difference between neutron and gamma from data taken after the DIN dissolution will be shown.
Neutrino oscillation experiments aim to measure the neutrino oscillation parameters with accuracy and achieve a complete understanding of neutrino physics. The determination of the neutrino oscillation parameters depends on the knowledge of the neutrino energy, which is reconstructed based on the particles in the final state that emerge out of the nucleus after the neutrino-nucleus interaction. This scattering becomes more complicated for the heavy nuclear targets(viz. Argon,
Calcium, etc.) that are being used by the current and upcoming neutrino oscillation experiments. In this work, we explore the viability of using machine learning algorithm (MLA) to improve the systematics due to mis-reconstrued neutrino energy and inherent nuclear effects in the heavy nuclear targets against the calorimetric method of neutrino energy reconstruction. We use data samples obtained from two neutrino event generators viz. GENIE and GiBUU to train the MLA.
We find the Ar/H ratio in an attempt to quantify nuclear effects in the Argon target, using the MLA we find that a combined data sample from both the neutrino event generators gives the ideal result.
The Liquid Argon Time Projection Chamber (LArTPC) detector technology has been used by many accelerator-based neutrino experiments. It offers excellent spatial and energy resolutions in detection of particles traversing the detector. This becomes particularly crucial for the low energy neutrino physics. However, extracting small signals from huge background in LArTPC waveforms is very challenging for low energy phenomena. It is important to understand the capability and threshold of reconstructing low energy signals in a LArTPC. Here, we consider a unique approach of using a simple 1D convolutional neutral network (1D-CNN) to look directly at raw waveforms from single wires in a LArTPC. We will present encouraging results in the application of a 1D-CNN to the task of finding the region-of-interest in LArTPC waveforms using ArgoNeuT data and show its capability to explore the low energy physics in LArTPC detectors.
New developments in liquid scintillators, high-efficiency, sub-nanosecond photon sensors, and chromatic photon sorting have opened up the possibility to realize large-scale neutrino detectors that can discriminate between Cherenkov and scintillation signals. A hybrid detector could exploit the two distinct signals to reconstruct particle direction and species using Cherenkov light while also having the excellent energy resolution and low threshold of a scintillator detector. Situated in a deep underground laboratory, and utilizing new techniques in computing and reconstruction techniques, a hybrid detector could achieve unprecedented levels of background rejection, thus enabling a rich physics program in long-baseline neutrino oscillations and the observation of astrophysical neutrinos.
This talk describes Theia, a detector design that incorporates these new technologies in a practical and affordable way. Moreover, it highlights the most recent achievements in the development of suitable scintillation materials and novel photo sensors.
The DUNE (Deep Underground Neutrino Experiment) is a proposed long-baseline
neutrino oscillation experiment located in the United States. The main physics objectives of DUNE are to characterize neutrino oscillations, search for nucleon decay, and observe supernova neutrino bursts. The DUNE far detector will be located 4850' underground at the Sanford Underground Research Facility in Lead, South Dakota. It will house the world's largest liquid argon time projection chamber. The DUNE Far Detector can be used to detect high-energy muons that arise
from interactions of cosmogenic neutrinos and search for neutrinos originating in the decays of Weakly Interacting Massive Particles (WIMPs). Selecting upward going muons reduces the background from cosmic-ray muons. The muon energy is estimated from the electromagnetic showers accompanying the muon, a technique that allows energy reconstruction up to a few hundreds of TeV. This work discusses the DUNE far detector's potential for neutrino astronomy.
Neutrinos have played a key role in astrophysics, from the characterization of nuclear fusion processes in the Sun to the observation of supernova SN1987A and multiple extragalactic events. The Super-Kamiokande experiment has played a major part in past in these astrophysical studies by investigating low energy O(10)~MeV neutrinos. It has notably been instrumental in characterizing the 8B solar neutrino spectrum and currently exhibits the best sensitivity to the diffuse neutrino background from distant supernovae. Low energy searches however face significant challenges due to important backgrounds from cosmic muon spallation. Reducing these backgrounds will require implementing state-of-the-art neutron tagging algorithms to discriminate between different types of interactions, as well as a thorough characterization of spallation-inducing mechanisms. Here, we present an in-depth study of spallation backgrounds, in particular of the showers produced by muons passing through the detector. This study, and in particular the implementation of new FLUKA-based simulations, are expected to significantly impact analysis strategies for a wide variety of low energy searches in Super-Kamiokande.
T2K (Tokai to Kamioka) is a long-baseline neutrino oscillation experiment located in Japan. One of the most challenging tasks of T2K is to identify whether CP is violated in the lepton sector, which T2K's recent results favour. By utilizing the near detector (ND280) data, T2K can constrain neutrino interaction and flux uncertainties by fitting a parametrised model to data. This allows a significant reduction of the systematic uncertainties in neutrino oscillation analyses. The fit to ND280 data currently uses several samples which are based on muon kinematics and pion multiplicity. There is ongoing work to expend these samples by incorporating the reconstructed proton multiplicity in order to enhance ND280 sensitivity to the nuclear physics processes which drive current systematic uncertainties. This talk outlines the properties of new ND280 samples and details how they will help reduce uncertainties.
The PIENU experiment was performed to measure the ${\pi}^+{\to}e^+{\nu}_e$ branching ratio with precision of $<0.1$% and search for rare pion decays. Recently many new and improved results of the rare decay searches involving heavy neutrinos ${\pi}^+{\to}l^+{\nu}_H(l=e,{\mu})$, weakly interacting neutral bosons ${\pi}^+{\to}l^+{\nu}X$, and three neutrinos ${\pi}^+{\to}l^+{\nu}_l{\nu}\bar{\nu}$ have been obtained. Search for exotic muon decay ${\mu}^+{\to}e^+X$ was also performed. Results of the searches will be presented.
Observation of geo-neutrinos originating from radioactive isotopes in the Earth (238U,232Th, etc.) can be converted to the amount of radioactive isotopes and the heat generated by their decays which governs the Earth dynamics.
KamLAND experiment achieved world's first observation of geo-neutrinos in 2005. Improvement of observation accuracy allowed us to reach the level where we can obtain geoscientific knowledge. However, it is hard to obtain information of the mantle because 70% of neutrinos observed by detector currently operating or planned are derived from the crust.
Ocean Bottom Detector can observe geo-neutrinos originating from the mantle directly. Unlike existing other neutrino detectors, OBD detects neutrinos on the seafloor. Given that the oceanic crust is thinner than the continental crust and has lower densities of U and Th, ~70% of anti-neutrinos at OBD come from the mantle. Another unique feature of OBD is keeping the distance from the reactors which are the main background sources for continental detectors. In addition, this movable detector can observe at multiple points in the ocean.
Scientists at the University of Hawaii started to discuss the idea of observing the geo-neutrinos on the sea floor 15 years ago as the detector called "Hanohano". Unfortunately, the idea has not been realized yet.
In 2019 joint research between Tohoku University and JAMSTEC was started to lead the comprehensive research relating to understanding the Earth's deep interior and realize OBD. We are now working for the prototype detector.
The IceCube Neutrino Observatory with its surface array IceTop enables multi-messenger astrophysics, detecting cosmic rays and neutrinos and searching for PeV gamma rays at a single location. IceTop will be upgraded in the coming years in order to improve its sensitivity and resolution. This surface enhancement will consist of 32 stations comprised of 8 scintillation panels and 3 radio antennas each. This array is designed to lower the detection threshold of IceTop and improve systematic uncertainties. In addition, with the radio antennas, it will reach maximum accuracy for the measurement of air showers of energies around the second knee of the cosmic-ray spectrum where a transition from galactic to extra-galactic sources is expected. A complete prototype station has been operating at the South Pole since 2020. In this talk, I will present the plan for this enhanced surface array and describe how it will function.
The Pacific Ocean Neutrino Experiment (P-ONE) is a new initiative between Canadian and German groups that aims to construct a large volume neutrino telescope in the Northeast Pacific Ocean and, in this way, complement the sky coverage of the existing or under construction neutrino telescopes. As part of the NEPTUNE observatory, established by ONC, two pathfinders were built and deployed at the Cascadia Basin node, which will host P-ONE. The first pathfinder STRAW (STRings for Absorption length in Water), deployed in June 2018, has measured the optical properties of the deep Pacific Ocean. Besides that, it is also monitoring the in-situ background rates due to K40 decay and bioluminescence. STRAW-b, the second pathfinder, aims to further characterize the deployment site with its specialized modules, among which are two LiDARs, three spectrometers, and a muon tracker. The talk covers technical details and preliminary results of both pathfinders and concludes with an P-ONE outlook.
The FAMU (Fisica degli Atomi Muonici) experiment has the goal to measure precisely the proton Zemach radius, with incoming low energy muons. It will contribute to precision tests of QED and may contribute to shed more light on the so-called proton radius puzzle, by studying the electromagnetic structure of the proton and muon-nucleon interactions. To this aim, the FAMU experiment makes use of a high-intensity pulsed muon beam at RIKEN-RAL impinging on a cryogenic hydrogen target with an high-Z gas admixture and a tunable mid-IR high energy laser, to measure the hyperfine (HFS) splitting of the 1S state of the muonic hydrogen. From the value of the exciting laser frequency, the energy of the HFS transition may be derived with high precision (10$^{-5}$) and thus, via new refined QED calculations, the Zemach radius of the proton. The experimental signature of the process will be the emission of characteristic X-rays from the de-excitation of the high-Z muonic atoms formed when the muon is transferred from p to Z in the cryogenic target. Preliminary studies have provided indications on the most suitable high-Z elements to be used and validated the experimental method and apparatus. The experimental apparatus includes a system of precise fiber-SiPM beam hodoscopes, a crown of 1" LaBr3 crystals read by photomultipliers complemented by additional 1/2" LaBr3 crystals read by SiPM arrays with temperature control and a few HPGe detectors for detection of the emitted characteristic X-rays around 100 keV . The system is in condition to detect the signal in a noisy environment and has been used for preliminary runs. The experimental apparatus and the innovative method to determine the Zemach proton radius with high precision will be described in detail.
The neutrino detection require an associated lepton birth signal. Because of the weak interaction and because of the abundant cosmic ray noises, in last century huge undergroung detector were preferred for the single lepton traces. However highest energies leptons (above tens-hundred TeV), electron or tau secondaries, might produce in air huge airshowers: such a huge amplified signal, in number and in area, makes PeV-EeV tau neutrinos better and easier to be discovered above the ground. Tau and UHECR airshowering at high altitude are often splitted by geomagnetic forces into two main pair spiral showers. Because of the Earth opacity to highest energy neutrino, Tau airshower were considered from deep valleys or Earth edges while sitting on mountains, balloons or satellites. Several present and future ongoing experiment should track such showering at horizons. Moreover also our far Moon offer a calorimeter to reveal UHE neutrinos: namely the possibility for tens or a hundred TeV muon neutrino to interact inside a few km in Moon crust, escape toward us as a muon, to decay in flight as an electron, leading on top of our atmosphere to a gamma-like shower just centered inside the moon shadows. Similar but much more rare higher energy tau (GZK EeVs) neutrino may shine to us unexpected UHECR, even in cluster, just toward the Moon. The widest Grand like array detector in construction on Earth could be in future be able to reveal such Moon-like astrophysical muon-electron signals. Future widest UHECR array might also reveal lunar tau secondariy traces.
Detecting ultrahigh-energy (UHE) neutrinos is a challenging task because fluxes are low, and the interaction cross-sections are minute. Motivated by the detection of high-energy neutrinos with IceCube, we are developing a compact Cherenkov telescope to detect Earth-skimming (UHE) neutrinos from a high-altitude balloon flight. The 1 m diameter Schmidt telescope has a 512-pixel silicon-photomultiplier (SiPMs) camera, read out with 100MS/s. The telescope will fly aboard the Extreme Universe Space Observatory Super Pressure Balloon 2 (EUSO-SPB2), a precursor to the proposed Probe of Extreme Multi-Messenger Astrophysics (POEMMA) mission. In this flash talk I will summarize the status of the Cherenkov telescope development and its expected performance.
The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton multi-purpose Liquid Scintillator (LS) detector currently being built in a dedicated underground laboratory in Jiangmen (PR China). JUNO’ s main physics goal is the determination of the neutrino mass ordering using electron anti-neutrinos from two nuclear power plants at a baseline of about 53 km. JUNO aims for an unprecedented energy resolution of 3% at 1 MeV for the central detector, to be able to determine the mass ordering with 3 - 4 $\sigma$ significance within six years of operation.
To achieve JUNO's goals, particularly high demands are placed on the Linear AlkylBenzene (LAB) based LS. As the high-purity scintillator and the liquid handling systems related to it are key technologies for the success of the experiment, this talk is mainly focused on their development. The foreseen LS purification steps are described as well as their technical realization in purification facilities. Furthermore, an overview on a prototype testing phase with smaller pilot facilities built up at the Daya Bay experimental site is discussed here as well.
Based on the experiences from the pilot plant phase, the design of an online monitoring detector for the radiopurity of the LS was carried out. The purpose of this detector called OSIRIS (Online Scintillator Internal Radioactivity Investigation System) are measurements of the scintillator’s internal radioactivity during the commissioning and operation of JUNO’s LS production and purification facilities. Therefore, also a brief overview of OSIRIS is presented in this talk.
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The Liquid Argon Time Projection Chamber (LArTPC) is increasingly becoming the chosen technology for both current and future precision neutrino oscillation experiments. One of the primary challenges in employing LArTPC technology is characterizing the performance of this technology and quantifying the associated systematic uncertainties. The MicroBooNE experiment plays a crucial role in understanding the technology by performing numerous measurements. These include identification and filtering of excess TPC noise, energy scale calibration, electron diffusion, recombination, and measurements of drift electron attenuation. MicroBooNE, residing on the surface, can also provide significant information about cosmic ray induced space charge in the TPC volume and the resulting distortions to the electric field. This talk will provide an overview of detector physics studies in MicroBooNE along with highlighting recent results. A brief introduction to the detector sub-systems, the procedure for calorimetric calibration in LArTPCs, and a novel technique for assessing detector systematics will also be presented
Current neutrino detectors will observe hundreds to thousands of neutrinos from a Galactic supernovae, and future detectors will increase the yield by an order of magnitude or more. With such a data set there is potential for a huge increase in our understanding of the explosions of massive stars, nuclear physics under extreme conditions, and the properties of the neutrino. However there is a large gulf between supernova simulations and the corresponding signals in detectors which will make any comparison between theory and observation very difficult. SNEWPY is an open-source software package which bridges this gap. The SNEWPY code can interface with simulation data to generate a time series of neutrino spectra at Earth which it can then process with the SNOwGLoBES software to calculate the neutrino event rates. SNEWPY will then collate the output from SNOwGLoBES into the observable channels of each detector. In this talk I give an overview of SNEWPY, demonstrate its current capabilities, and discuss our plans for future directions.
The recent detection of the coherent elastic neutrino-nucleus scattering (CEνNS )opens the possibil- ity to use neutrinos to explore physics beyond standard model with small size detectors. However, the CEνNS process generates signals at the few keV level, requiring of very sensitive detecting technologies for its detection.
The European Spallation Source (ESS) has been identified as an optimal source of low energy neutrinos offering an opportunity for a definitive exploration of all phenomenological applications of CEνNS. In this project I propose apply the high pressure xenon gas TPC technology to the detection of the CEνNS process at the ESS. This will require the development of very low-energy detectors and to improve the current knowledge of the quenching factor for nuclear recoils in xenon gas at keV energies. The major goal of this project is to build a 20 kg xenon gaseous detector and operate it at the ESS, such detector will provide more than 7,000 CEνNS events per year, overtaking the sensitivities of much larger detectors in current spallations sources.
In this talk I’ll present the advantages of the gaseous TPC technology to exploit the physics of the CEνNS process and the experimental program towards the construction and operation of a gaseous detector at the ESS.
Developed as NASA Astrophysics Probe-class mission, the Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is designed to observe cosmic neutrinos and to identify the sources of ultra-high energy cosmic rays (UHECRs) with full-sky coverage for both of these extremely energetic messengers. POEMMA consists of two spacecraft flying in a loose formation at 525 km altitudes. Each spacecraft hosts a large Schmidt telescope with a novel focal plane optimized to observe both the beamed, optical Cherenkov signals from extensive air showers (EASs) and the near-UV fluorescence signal from EASs. In neutrino limb-viewing Cherenkov mode, POEMMA will be sensitive to cosmic tau neutrinos above 20 PeV by observing the upward-moving EASs induced from tau neutrino interactions in the Earth. POEMMA is designed to quickly re-orient to a Target-of-Opportunity (ToO) neutrino mode to view and follow transient astrophysical sources with exceptional flux sensitivity with full-sky coverage. In UHECR stereo fluorescence mode, POEMMA will have remarkable sensitivity to UHE neutrinos above 20 EeV and will measure the spectrum, composition, and full-sky distribution of the UHECRs above this energy. POEMMA’s neutrino measurement capabilities will be discussed along with a summary of POEMMA’s instrument & mission designs and UHECR measurement performance.
Cosmic-ray accelerators capable of reaching ultra-high energies are expected to also produce very-high energy neutrinos via hadronic interactions within the source. Many of the candidate astrophysical source classes are either transient in nature or exhibit flaring activity. Leveraging the Earth as a neutrino converter, the Probe of Extreme Multi-Messenger Astrophysics (POEMMA) will be able to detect cosmic tau neutrinos at energies ~ 10 PeV and above. As a space-based mission, POEMMA will have orbital characteristics and slewing capability that will ensure full-sky coverage and enable rapid follow up, making it uniquely suited for searching for neutrinos from astrophysical transient events. We present the latest results of a study exploring the prospects of detecting tau neutrino events with POEMMA from a variety of astrophysical transient source classes and potential backgrounds during Target-of-Opportunity observations.
The Trinity Observatory is a proposed ultra high energy (UHE) neutrino detector with a core-energy range of 10^6 GeV-10^10 GeV, bridging the observational gap between IceCube and radio UHE detectors like GRAND. It is a system of air-shower imaging telescopes that detect Earth-skimming tau neutrinos from multiple mountain tops. The telescopes have a novel-design 10x60-degree rectangular wide field of view optics each, that image air-shower onto a 3,300-pixel curved-profiled SiPM camera. Trinity’s primary science objectives are the extension of the IceCube measured neutrino flux to UHE and the detection of cosmogenic neutrinos. In this contribution, we focus on the current design of Trinity and discuss its performance.
NOvA is a long-baseline neutrino experiment that measures oscillation using the muon neutrinos and antineutrinos delivered by the NuMI beam at Fermilab. Neutrino oscillation is detected by observing appearance of electron (anti)neutrinos and disappearance of muon (anti)neutrinos at the Far Detector located near Ash River, MN, as compared to the Near Detector at Fermilab.
In this talk, I will present the joint analysis of neutrino and antineutrino oscillation measurement in the three-flavor paradigm and highlight the latest constraints on neutrino mass ordering, mixing parameters and CP phase violation in leptons, by the NOvA experiment.I will also outline the planned upgrades and the future measurement sensitivity of the experiment.
T2K (Tokai to Kamioka) is a Japan based long-baseline neutrino oscillation experiment designed to measure (anti-)neutrino flavor oscillations. A neutrino beam peaked around 0.6 GeV is produced in Tokai and directed toward the water Cherenkov detector Super-Kamiokande, which is located 295 km away. A complex of near detectors is located at 280 m and is used to constrain the flux and cross-section uncertainties by measuring the neutrinos before oscillations. In 2014, T2K started a campaign to measure the phase $\delta_{CP}$, an unknown element of the Pontecorvo-Maki-Nakagata-Sakata matrix, that can provide a test of the violation or conservation of the CP symmetry in the neutrino sector. To achieve this goal, T2K is taking data with a neutrino and antineutrino enhanced beam investigating asymmetries in the electron neutrino and antineutrino appearance probabilities. The most recent result obtained combining data taken with a neutrino and antineutrino beam showed that the CP-conserving cases are excluded at 90% confidence level. In this presentation the methodology employed to reach this result is outlined with particular emphasis on the measurement of the flux and cross-section uncertainties at the T2K near detector. One of the largest systematic uncertainties in T2K oscillation analysis comes from present limited knowledge of (anti-)neutrino-nucleus cross-sections. Neutrino scattering understanding is crucial for the interpretation of neutrino oscillation and details on how is treated and its impact on T2K oscillation analysis are discussed in this presentation.
T2K (Tokai to Kamioka) is a Japan-based long-baseline neutrino oscillation experiment designed to measure (anti-)neutrino flavor oscillations. After the measurement of a non-zero value of the mixing angle $\theta_{13}$, T2K has started a campaign to measure the phase $\delta_{CP}$, an unknown element of the Pontecorvo-Maki-Nakagata-Sakata matrix, that can provide a test of the violation or conservation of the CP symmetry in the neutrino sector. To achieve this goal, T2K is taking data with a neutrino and antineutrino enhanced beam investigating asymmetries in the electron neutrino and antineutrino appearance probabilities. Such ability to run with different beam mode, also allows the experiment to separately extract for neutrinos and antineutrinos the oscillation parameters $\delta m_{32}$ and $\theta_{23}$ analyzing the muon (anti)neutrino disappearance channels. No significant differences between the survival probabilities of muon neutrino and anti-neutrino are expected in T2K according to the standard 3 flavor oscillation model, so a difference could be interpreted as possible CPT violation and/or non-standard interactions. In this presentation the latest T2K results on these searches, obtained analyzing the data taken in both beam modes, are described. An analysis using an effective two-flavor neutrino oscillation model, where $\sin^2\theta$ is allowed to take non-physical values larger than 1, is discussed as well. This analysis has as goal to check the consistency of our data with the three-flavor model neutrino oscillation framework.
The measurement of an astrophysical flux of high-energy neutrinos by IceCube is an important step towards finding the long-sought sources of cosmic rays. Nevertheless, the long exposure neutrino sky map shows no significant indication of point sources so far. This may point to a large population of faint, steady sources or flaring objects as origins of this flux. The most compelling evidence for a neutrino point source so far is the recent observation of the flaring gamma-ray blazar TXS 0506+056 in coincidence with a high-energy neutrino from IceCube. This is a result of a Neutrino Target of Opportunity (NToO) program in which all currently operating Imaging Atmospheric Cherenkov Telescopes (IACTs) take part. The case for TXS 0506+056 being a neutrino source was made stronger by evidence of a 5-month long neutrino flare in 2014-2015.
Here we investigate the chances of a detection of a gamma-ray counterpart to a neutrino source with the future Cherenkov Telescope Array (CTA), as a result of a follow-up observation of a neutrino alert. We use the FIRESONG software to simulate different neutrino sources populations, which could be responsible for the diffuse flux of astrophysical neutrinos as measured by IceCube. We scan over parameters that can be used to describe the populations such as luminosity and density (density rate) for steady (flaring) objects. Several CTA array layouts and instrument response functions are tested in order to derive optimal follow-up strategies and the potential science reach of the NToO program for CTA. We find that following neutrino alerts by IceCube, in certain parameter space regions, CTA has a very high per alert probability of detecting a matching steady source. What is more, using a model by Halzen et al. (2018), for neutrino flares similar to that of 2014-2015, we find that CTA will detect a counterpart in more than a third of the alerts.
The gamma-ray blazar TXS 0506+056 was discovered in very high energy (>100 GeV) gamma-rays by the MAGIC telescopes in 2017 in a coincidence with a high energy neutrino event IC-170922A. Subsequent multiwavelength (MWL) observations and theoretical modeling suggest that this source could be a cosmic ray and neutrino emitter. So far, this is the most significant association between a high-energy neutrino and an astrophysical source emitting gamma rays and X-rays. Through accurate and contemporaneous MWL spectral measurements of TXS 0506+056, we can test the connection between the high-energy neutrinos and blazars. We present the light curves and simultaneous spectral energy distributions from the MAGIC and MWL monitoring of this source, from November 2017 till February 2019, together with the theoretical interpretation of these observations. We discuss their implications on cosmic-ray accelerations in AGN and on the physics of relativistic jets from supermassive black holes.
In view of the IceCube's 6-year high-energy starting events (HESE) sample,
we revisit the possibility that the updated data may be better explained
by a combination of neutrino fluxes from dark matter decay and an
isotropic astrophysical power-law than purely by the latter. We find
that the combined two-component flux qualitatively improves the fit
to the observed data over a purely astrophysical one, and discuss how
these updated fits compare against a similar analysis done with the
4-year HESE data. We also update fits involving dark matter decay
via multiple channels, without any contribution from the astrophysical
flux. We find that a DM-only explanation is not excluded by neutrino
data alone. Finally, we also consider the possibility of a signal
from dark matter annihilations and perform analogous analyses to
the case of decays, commenting on its implications.
The IceCube Neutrino Observatory detects neutrinos by collecting the Cherenkov light created by their interaction products within one cubic km of ice. Neutrinos of a particular flavor produce corresponding charged leptons in charged current (CC) interactions. Each type of lepton can create a distinct light emission pattern in the detector. The hardest to observe is the pattern of the tau neutrino CC interaction. It strongly resembles electron and neutral current neutrino interactions, except at the highest energies (>10PeV). This work aims to improve collaboration’s previous attempts to distinguish the two signatures at lower energy (0.1 to 10 PeV) using deep learning. We represent each neutrino interaction as a set of three 2D images and train a convolutional neural network to separate the ones belonging to tau neutrinos. If successful, the work can improve the measurement of astrophysical tau neutrino flux and astrophysical neutrino flavor composition on Earth.
A neutrino source based on decay of an intense muon beam would make an ideal source for measurement of neutrino oscillation parameters. Muon beams may be created through the decay of pions produced in the interaction of a proton beam with a target. The muons are subsequently accelerated and injected into a storage ring where they decay producing a beam of neutrinos. Cooling of the muon beam would enable more muons to be accelerated resulting in a more intense neutrino source. Ionization cooling is the novel technique by which it is proposed to cool the beam. The Muon Ionization Cooling Experiment collaboration has constructed a section of an ionization cooling cell and used it to provide the first demonstration of ionization cooling. Here the observation of ionization cooling is described. The cooling performance is studied for a variety of beam and magnetic field configurations. The future outlook for muon ionization cooling demonstrations is discussed.
The ENUBET experiment, included in the CERN Neutrino Platform effort as NP06/ENUBET, is developing a new neutrino beam based on conventional techniques in which the flux and the flavor composition are known with unprecedented precision ($\mathcal{O}$(1%)). Such a goal is accomplished by monitoring the associated charged leptons produced in the decay region of the ENUBET facility. Positrons and muons from kaon decays are measured by a segmented calorimeter instrumenting the walls of the decay tunnel, while muon stations after the hadron dump can be used to monitor the neutrino component from pion decays. Furthermore, the narrow momentum width (<10%) of the beam provides a precise measurement ($\mathcal{O}$(10%)) of the neutrino energy on an event by event basis, thanks to its correlation with the radial position of the interaction at the neutrino detector. ENUBET is therefore an ideal facility for a high precision neutrino cross-section measurement at the GeV Scale, that could enhance the discovery potential of the next generation of long-baseline experiments, and for the study of non-standard neutrino models.
We report here a new improved design of the proton target and of the meson transfer line, that ensures a larger neutrino flux while preserving a purity in the lepton monitoring similar to the one previously achieved. The final design of the ENUBET demonstrator for the instrumented decay tunnel, which is due by the end of 2021, will be also discussed. It has been determined on the basis of the results of the 2016-2018 testbeams and will prove the scalability and performance of the selected detector technology. Progress on the full simulation of the ENUBET facility and of the lepton reconstruction, towards the full assessment of neutrino flux systematics, will be also reported.
The nuSTORM facility uses a stored muon beam to generate a neutrino source. Muons are captured and stored in a storage ring using stochastic injection. The facility will aim to measure neutrino-nucleus scattering cross sections with uniquely well-characterised neutrino beams; to facilitate the search for sterile neutrino and other Beyond Standard Model processes with exquisite sensitivity; and to provide a muon source that makes an excellent technology test-bed required for the development of muon beams capable of serving as a multi-TeV collider. In this paper we describe the latest status of the development of nuSTORM, the R&D needs, and the potential for nuSTORM as a Muon Collider test facility.
The 5 MW ESSnuSB proton beam represents an outstanding opportunity to create a sufficiently intense neutrino Super Beam to enable measurement of leptonic CP violation with a megaton water Cherenkov detector placed at the three time more distant second neutrino oscillation maximum, where the CP-violating term in the neutrino oscillation probability is significantly larger at the oscillation peak as compared to the first oscillation maximum peak. This is of decisive significance as the accuracy in the measurements of CP-violation phase is notoriously limited by the systematic errors. The main components of ESSnuSB Near Detector are a water Cherenkov detector, a Super Fine Grain Detector made of small plastic cubes and a Nuclear Emulsion detector and the Far Detector of two large water Cherenkov detectors of together 500 megaton fiducial volume. The progress on the design and simulations of these detectors will be reviewed as well as the physics potential of ESSnuSB, in particular for the discovery of CP violation and precision measurement of its phase angle helping to discriminate between different lepton flavour models.
We present results of searches for light sterile neutrino oscillations at RENO. We have conducted a sub-ev scale sterile neutrino oscillation search using the RENO far and near detector data and an eV scale sterile neutrino oscillation search combining the RENO and NEOS data. The identical RENO near and far detectors are located at 294 m (near) and 1383 m (far), respectively, from the center of the reactor array of the Hanbit Nuclear Power Plant. The NEOS detector is located at 24m from the core of the fifth reactor in the same power plant. An observed prompt-spectral difference between RENO near and far detectors is found to be consistent with that of the three-flavor oscillation model, and thus yields 95% C.L. limits on $\sin^2 2θ_{14}$ in the $10^{−4} ≲ |\Delta m^2_{41}| ≲ 0.5\, \text{eV}^2$. Based on the spectral comparison between RENO and NEOS spectra, we obtain a 90% C.L. excluded region of $10^{−3} ≲ |\Delta m^2_{41}| ≲ 7\,\text{eV}^2$. We also obtain a 68% C.L. allowed region with the best fit of $|\Delta m^2_{41}| = 2.37 \pm 0.03 \, \text{eV}^2$ and $\sin^2 2\theta_{14}=0.09 \pm 0.03 $ with p-value 13% for the three-flavor oscillation model as a null hypothesis. Comparisons of obtained reactor antineutrino spectra at reactor sources are also made among RENO, NEOS and Daya Bay to find a possible spectral variation.
The existence of massive or massless weakly interacting neutral particles $X$ such as axion-like particles, sterile neutrinos, and Majorons has been suggested to augment the standard model with motivations that include providing dark matter candidates, explaining baryogenesis, and revealing the origin of neutrino masses. The three body pion decays ${\pi}^+{\to}l^+{\nu}X(l=e,{\mu})$ involving such particles were sought in the PIENU experiment with order of magnitude improved sensitivity over the previous experiment. The result of the searches and prospects of the PIENU experiment will be presented.
The JSNS2 (J-PARC Sterile Neutrino Search at the J-PARC Spallation Neutron Source) experiment will search for neutrino oscillations over a short 24 m baseline with delta m square near 1 eV square at the J-PARC Materials and Life Science Experimental Facility. The JSNS2 detector is filled with 17 tons of gadolinium-loaded liquid scintillator (LS) with an additional 31 tons of unloaded LS in the intermediate gamma-catcher and outer veto. A 1 MW proton beam (3 GeV) incident on a mercury target produces an intense neutrino beam from muon decay-at-rest. The experiment will search for muon antineutrino to electron antineutrino oscillations, detected via the inverse beta decay reaction (electron antineutrino + proton -> positron + neutron), which is then tagged by the distinctive gammas from neutron capture on gadolinium. JSNS2 is expected to provide the ultimate test of the LSND anomaly by replicating nearly identical conditions with a much better S/N ratio. JSNS2 has physics data in June 2020, and also has taken data currently since Jan. 2021 with scintillator filled. And we have a plan for constructing another detector as a 2nd phase of the experiment (JSNS2-II). The 2nd detector will be filled with 35 tons of Gd-LS, and have a 48m baseline. Analysis using both 2 detectors will give significantly better sensitivity, especially in low Delta m^2 region with the longer baseline than the 1st detector. In this talk, we will summarize the detector operation (including scintillator filling&extraction), data acquisition & preliminary analysis status from physics data, and plan for JSNS2-II.
The detailed analysis of the results of the Neutrino-4 experiment obtained from the beginning of the experiment in 2016 to the present is presented. The analysis was carried out on all statistical material. The main task of the analysis performed is to identify possible systematic errors of the experiment. The result of analysis will be presented.
Heavy Neutral Leptons (HNLs) can be abundantly produced in the sky when cosmic rays impact our atmosphere. In this talk, we present new constraints derived for the signal originating from the decay of these HNLs inside the volume of large Neutrino Telescopes such as IceCube and Super-Kamiokande.
Dark matter can produce a high-energy neutrino flux through decay or annihilation, that can be observed by current and future neutrino telescopes. The neutrino flux from astrophysical, atmospheric and dark matter origin can be distinguished through their different angular distributions, since the dark matter signal will have some correlation with the galactic center. We use the difference in angular distributions to probe a dark matter signal through an angular power spectrum analysis. We simulate skymaps with through-going muon neutrino events above 60TeV, where we consider both extra-galactic and galactic dark matter contributions. I will show that the angular power spectrum analysis offers a solid and powerful way to assess dark matter signals with current (IceCube) and future (IceCube-Gen2, KM3NeT) neutrino data. KM3NeT is especially sensitive to low dark matter masses due to its visibility towards the galactic center and we further investigate lower energies down to 100GeV.
Cosmic-rays interacting with nucleons in the solar atmosphere create pions, kaons, and other particles which produce a flux of high-energy neutrinos. Predictions for this flux exist in the literature, but it has yet to be measured by neutrino observatories. Since this flux is an irreducible background for solar WIMP searches currently being carried out by neutrino telescopes, its magnitude sets a sensitivity floor for these searches. Furthermore, the detection of these neutrinos would allow neutrino telescopes to measure neutrinos in yet-unprobed oscillation regimes, characterized by a ratio of baseline to the energy of L/E~150e6km/1TeV~1e5km/GeV. In this contribution, we will present the status of a new IceCube event selection optimized to detect these neutrinos.
While there is evidence for the existence of dark matter, its properties have yet to be discovered. Similarly, the nature of high-energy astrophysical neutrinos detected at the IceCube Neutrino Observatory remains unresolved. If dark matter and neutrinos are coupled to each other, they may exhibit a non-zero elastic scattering cross section. Such an interaction between an extragalactic neutrino flux and dark matter would be concentrated in the galactic centre, where the dark matter column density is the greatest. This scattering would attenuate the flux of high energy neutrinos, which could be observed at the IceCube Neutrino Observatory. Using TeV to PeV neutrinos, we perform an unbinned likelihood analysis using the seven-year medium energy starting event (MESE) cascade dataset to explore the sensitivities to this indirect detection of dark matter for four possible DM-neutrino interaction scenarios.
https://mediaspace.unipd.it/media/XIX+International+Workshop+on+Neutrino+Telescopes+- +Parallel+Room+2/1_aa50wgn2?st=7304&ed=7639
Long-duration gamma-ray bursts (GRBs) have been subject of investigation for a long time, being among the most mysterious and powerful transients occurring in our universe. In the attempt of explaining the observed electromagnetic GRB emission, various models have been proposed, even if an exhaustive theoretical explanation of the mechanism powering GRBs is still lacking. GRBs are also candidate sources of ultra-high energy cosmic rays and high energy neutrinos. In this work, we show that, although different jet models may be equally successful in fitting the observed electromagnetic spectral energy distributions, the neutrino production strongly depends on the adopted emission and dissipation model. To make a fair comparison of the neutrino production across models we compute the neutrino emission for a benchmark high-luminosity GRB in various jet emission and dissipation scenarios. In particular, we consider an internal shock model, a dissipative photosphere model in the presence of internal shocks, a three-component model with emission arising from the photosphere, the IS, and external shock, and the internal-collision-induced magnetic reconnection and turbulence model. We also compute, for the first time, the neutrino signal expected in two models where the jet is assumed to be magnetically dominated, namely a magnetized jet model with gradual dissipation, and the recently proposed proton synchrotron emission model. We find that the expected neutrino fluence can vary up to 1–1.5 orders of magnitude in amplitude and peak at energies ranging from $10^{4}$ GeV to $10^{8}$ GeV. For our benchmark input parameters, none of the explored GRB models is excluded by the targeted searches carried out by the IceCube and ANTARES Collaborations. This work highlights the great potential of neutrinos in pinpointing the GRB emission mechanism in the case of successful neutrino detection and the importance of relying on different jet models for unbiased stacking searches.
The neutrino mass ordering (NMO) is one of the fundamental questions in neutrino physics. KM3NeT/ORCA and JUNO are two neutrino oscillation experiments both aiming at measuring the NMO with different approaches: ORCA with atmospheric neutrinos transversing matter/Earth and JUNO with reactor neutrinos. This talk presents the potential of determining the NMO through a combined analysis of JUNO and ORCA data. In a joint fit, the NMO sensitivity is enhanced beyond the simple sum of the sensitivities of each experiment due to the tension between their $\Delta m_{31}^2$ best fit in a wrong ordering assumption. From this analysis, we expect to determine the true NMO with $5~\sigma$ significance after $1~-~2$ years of data taking by both experiments for the current global best-fit values of the oscillation parameters, while maximally 6 years will be needed for any other parameter set.
After a decade of Highest Energy Neutrino records at several tens TeV in Icecube we had no observed among first hundred of events,(exept an unique delayed neutrino-gamma 2017 flare) any sharp correlated brightest gamma-neutrino event. Icecube maps and events did not reveal any galactic plane signature, no significant tau double bangs. On the contrary Icecube found a remarkable
and comparable electro-muon flavor presence. All these almost missing imprint for any astrophysics are pointing to the ruling discover of the atmospheric charm neutrino signature able to smear and hide the underline astrophysical one.
One of the crucial aspects to reach the aimed energy resolution of 3% @ 1 MeV in the JUNO experiment will be the instrumentation with and performance of the used photo sensors in the detector. Up to 20’000 20-inch photomultiplier tubes (PMTs) will be deployed in JUNO, of which each of them moreover has to fulfil dedicated quality requirements for several key characteristics (dark rate, PDE, peak-to-valley ratio etc.). For that purpose, two independent PMT testing systems have been developed: a PMT mass testing facility based on commercial shipping containers, capable to characterize all 20’000 PMTs individually, as well as a photocathode scanning system for uniformity and high resolution tests of at least a large subsample of PMTs.
In this talk we shortly present the setups used for the PMT characterization and report about status, progress and preliminary results of the PMT testing campaign for JUNO.
The Online Scintillator Internal Radioactivity Investigation System (OSIRIS) is a 20-ton liquid scintillator detector currently under construction at the Jiangmen underground neutrino observatory (JUNO) in Kaiping, China. OSIRIS features 76 newly developed, intelligent PMTs (iPMTs) surrounding a cylindrical acrylic vessel embedded in a Cherenkov muon Veto. Its main purpose is the monitoring of the radiopurity of the liquid scintillator during the filling phase of JUNO. To achieve this goal, a rigorous calibration of OSIRIS is necessary. For this purpose, two independent calibration systems are introduced: On the one hand, a distributed Laser calibration system, as well as an automated calibration unit (ACU) based on a similar system from Daya Bay featuring three calibration capsules containing a low activity radioactive source, a high activity radioactive source and an optical calibration source.
In this talk we give a short introduction into the OSIRIS detector, its calibration systems, and the planned calibration modes.
ProtoDUNE Single-Phase (ProtoDUNE-SP) is a prototype of the first DUNE Far Detector module and was in operation at CERN from 2018-2020. As a liquid argon time projection chamber (TPC), ProtoDUNE-SP needs numerous calibration methods to measure the location of argon ionization and the precise number of electrons ionized. To aid in calibration, an array of scintillator strips covering the front and back TPC faces, known as a Cosmic Ray Tagger (CRT), was installed to externally tag cosmics, a major background for on-the-surface liquid argon TPC detectors. This talk will discuss the techniques ProtoDUNE-SP employs to calibrate the detector using the CRT and how the results of these studies inform the eventual performance of the DUNE Far Detector modules. Specifically, it will describe how ProtoDUNE-SP uniquely utilizes the CRT to measure offsets in the reconstructed track position and to quantify the attenuation of TPC signals due to liquid argon impurities.
Given the J-PARC program of upgrades of the beam intensity, the T2K collaboration is preparing towards an increase of the exposure aimed at establishing leptonic CP violation at 3 $\sigma$ level for a significant fraction of the possible $\delta_{CP}$ values. To reach this goal, an upgrade of the T2K near detector ND280 has been launched to reduce the overall statistical and systematic uncertainties at the appropriate level of better than 4%.
We have developed an innovative concept for this neutrino detection system, comprising the fully active Super-Fine-Grained-Detector (SuperFGD), two High Angle TPC (HA-TPC), and six TOF planes.
The HA-TPC will be used for 3D track reconstruction, momentum measurement, and particle identification. These detectors will increase near detector angular acceptance resulting in systematic uncertainty reduction in the neutrino oscillation measurements.
Two HA-TPCs with overall dimensions of 2x2x0.8 m3 will be equipped with 32 resistive MicroMegas. The thin field cage (3 cm thickness, 4% rad. length) will consist of composite material with a Kapton foil with copper strips to minimize the material budget between neutrino target and HA-TPC. The 34x42 cm2 resistive bulk MicroMegas will use a 200 kOhm/square DLC foil to spread the charge over the pad plane. The charge spread will allow to reaching precise track position reconstruction thus accurate momentum measurements, keeping pad size at 1cm2. The front-end cards, based on the AFTER chip, will be mounted on the back of the MicroMegas and parallel to its plane.
The first resistive MicroMegas modules have been tested in a test beam at CERN and DESY. Results of these test beams will be shown in this talk.
Dual Calorimetry is a technique designed for high precision control of detector calorimetry systematics. It is embodied at JUNO as two independent photosensors and readout systems with different photon occupancy regimes surrounding the 20 kton liquid scintillator. One is the ~18,000 20-inch large PMTs (LPMTs) system, and the other is the ~26,000 3-inch small PMTs (SPMTs) system. The LPMT system is designed for maximal light detection in order to achieve 3% energy resolution at 1MeV. The SPMT system, as the second calorimetry, is introduced to disentangle the degeneracy of calorimetry responses, isolate the charge non-linearity effects and provide a linear charge reference for LPMT. The Dual Calorimetry technique provides robust LPMT charge non-linearity calibration, thus helping the overall systematics control and physics measurement of JUNO. In this flash talk, the physics motivation, basic principle and potential performance of the Dual Calorimetry will be presented.
Detector systems fully or partially composed of solid polystyrene-based scintillator bars are used in many experiments. Given their wide variety of applications it is important to deepen our understanding of how scintillator performance changes with time. The long baseline neutrino experiment T2K (Tokai to Kamioka) has collected data since 2010. Most of the subsystems of the off-and on-axis near detectors, ND280 and INGRID, both located at J-PARC, 280m downstream from the proton beam target, are composed of scintillators of different shapes and origin. The data they have collected provide an opportunity to perform comprehensive studies of scintillator ageing. New studies of the ageing of the scintillator detectors of ND280 and INGRID are reported in this talk. Muon data recorded throughout the lifetime of the experiment were used to measure the decrease in light yield over time.
The Deep Underground Neutrino Experiment (DUNE) is an international experiment
dedicated to addressing some of the unanswered questions at the forefront of particle physics. DUNE will search for the Charge-Parity (CP) symmetry violation in the leptonic sector while measuring the oscillation probabilities of neutrinos and antineutrinos which will help us understand the preponderance of matter over antimatter in the universe, the dynamics of the supernovae and deliver world-leading results in solar neutrinos. One of the calibration systems proposed for DUNE is the neutron generator based Pulsed Neutron Source (PNS) system. Neutron captures provide a fixed energy deposition for calibrating the energy scale and energy resolution spatially and temporally across the tremendous DUNE volume. The first test for the PNS system was performed using a deuterium-deuterium neutron generator (DDG) at ProtoDUNE Single Phase detector in summer 2020, to test our neutron transport model and help develop neutron capture reconstruction algorithms. In this talk, I will discuss the motivation for such a calibration system for DUNE and present some preliminary results from the test.
Hyper-Kamiokande (HK) is the next generation large volume water Cherenkov detector under construction in Japan. Its physics program includes nucleon decay, neutrinos from astronomical and accelerator, with the main focus to determine the leptonic CP violation, with a fiducial volume, that is 8 times larger than its precursor Super-Kamiokande (SK).
To detect the weak Cherenkov light generated by neutrino interactions or proton decay, in addition to the 20'' PMTs as used in SK, the employment of the multi-PMT(mPMT) concept, consisting of 3'' PMTs, readout electronics and power inside a pressure vessel firstly introduced in the KM3NeT detector, is considered. Indeed, it offers several advantages as increased granularity, reduced dark rate, weaker sensitivity to Earth magnetic field, improved directional information and timing resolution with an almost isotropic field of view.
In this contribution the development of a mPMT module for HK is presented.
A measurement of the transmission coefficient for neutrons through a thick ($\sim 3$ atoms/b) liquid natural argon target in the energy range $30$-$70$ keV was performed by the Argon Resonance Transmission Interaction Experiment (ARTIE) using a time of flight neutron beam at Los Alamos National Laboratory.
In this energy range theory predicts an anti-resonance in the $^{40}$Ar cross section near $57$ keV, but the existing data, coming from an experiment performed in the 90s (Winters. et al.), does not support this.
This discrepancy gives rise to significant uncertainty in the penetration depth of neutrons through liquid argon, an important parameter for next generation neutrino and dark matter experiments.
In this talk, the first results from the ARTIE experiment will be presented.
The ARTIE measurement of the total cross section as a function of energy confirms the existence of the anti-resonance near $57$ keV, but not as deep as the theory prediction.
The Deep Underground Neutrino Experiment (DUNE) is a cutting-edge experiment for
neutrino science and proton decay studies. The single-phase liquid argon prototype detector at CERN (ProtoDUNE-SP) is a crucial milestone for DUNE that will inform the construction and operation of the first and possibly subsequent 17-kt DUNE far detector modules. Michel electrons are distributed uniformly inside the detector and serve as a natural and powerful sample to study the detector’s response for low-energy (tens of MeV) interactions as a function of position. I will present the current status of reconstructing Michel electrons from the decays of cosmic-ray muons in the ProtoDUNE-SP detector. We have developed selection tools to identify and reconstruct such Michel electrons which could benefit any LArTPC experiment generically.
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino oscillation experiment designed to measure CP violation in neutrinos and the neutrino mass hierarchy among other BSM goals. DUNE's far detector modules are based on liquid argon TPC (LArTPC) technology. ProtoDUNE-SP is DUNE's large scale single-phase prototype operated at the CERN Neutrino Platform. ProtoDUNE-SP has finished its Phase-1 running in 2020 and has successfully collected test beam and cosmic ray data. In this talk, I will discuss the first results on ProtoDUNE-SP Phase-1's physics performance.
Blazars whose low-energy spectral component peaks above ~0.4 keV are thought to be efficient particle accelerators and are known as extreme blazars. They are particularly interesting for high-energy astrophysics, as they may be the counterparts of very high-energy gamma-ray sources and high-energy astrophysical neutrinos. 3HSP J095507.9+355101 is the first extreme blazar to be possibly associated with a high-energy neutrino (IceCube-200107A) while undergoing a hard X-ray flare. Motivated by this observation, we perform detailed multi-messenger modeling of 3HSP J095507.9+355101 to assess the expected neutrino emission of the source during its recent X-ray flare and in the entire lifetime of IceCube operations. We focus on one-zone leptohadronic models, but we also explore alternative scenarios: (i) a blazar-core model, which considers neutrino production in the inner jet, close to the supermassive black hole; (ii) a hidden external-photon model, which considers neutrino production in the jet through interactions with photons from a weak broad line region; (iii) a proton synchrotron model, where high-energy protons in the jet produce gamma-rays via synchrotron; and (iv) an intergalactic cascade scenario, where neutrinos are produced in the intergalactic medium by interactions of a high-energy cosmic-ray beam escaping the jet. We find that the Poisson probability to detect one muon neutrino in ten years from 3HSP J095507.9+355101 with the real-time IceCube alert analysis is ~1% with our most optimistic leptohadronic scenario. Meanwhile, detection of one neutrino during the 44-day-long high X-ray flux-state period following the neutrino detection is only 0.06 %. The most promising scenarios for neutrino production also predict strong intra-source gamma-ray attenuation above 100 GeV. If the association is real, then IceCube-Gen2 and other future detectors should be able to provide additional evidence for neutrino production in 3HSP J095507.9+355101 and other extreme blazars.
Acceleration of cosmic rays in hot and magnetized coronae of active galactic nuclei will lead to the production of high-energy neutrinos and soft gamma rays. These optically thick environments, hidden in gamma-rays, are the promising environment for producing the flux of high-energy cosmic neutrinos at medium energies. In this talk, we present the high-energy cosmic neutrinos flux from the bright nearby Seyfert galaxies based on X-ray observations and evaluate their detestability in current and future neutrino telescopes. We show that NGC 1068, the most significant source in IceCube 10 year time-integrated search, is the most promising source among the bright nearby Seyfert galaxies and present scenarios identifiable in the current generation of neutrino telescopes. Moreover, we show that stacking searches will have sufficient sensitivity to identify the hidden cores of supermassive black holes as the dominant sources of high-energy neutrino emission at medium energy ranges.
I discuss the potential of current and future liquid scintillator neutrino detectors of $\mathcal O (10)$ kt mass to localize a presupernova neutrino signal in the sky. In the hours preceding the core collapse of a nearby star (at distance $D$ less than 1 kpc), tens to hundreds of inverse beta decay events will be recorded, and their reconstructed topology in the detector can be used to estimate the direction to the star. Although the directionality of inverse beta decay is weak ($\sim$ 8% forward-backward asymmetry for currently available liquid scintillators), we find that for a fiducial signal of $200$ events (which is realistic for Betelgeuse), a positional error of $\sim$ 60$^\circ$ can be achieved, resulting in the possibility to narrow the list of potential stellar candidates to less than ten, typically. For a configuration with improved forward-backward asymmetry ($\sim$ 40%, as expected for a lithium-loaded liquid scintillator), the angular sensitivity improves to $\sim$ 15$^\circ$, and -- when a distance upper limit is obtained from the overall event rate -- it is in principle possible to uniquely identify the progenitor star. Any localization information accompanying an early supernova alert will be useful to multi-messenger observations, dark matter detection experiments and to particle physics tests using collapsing stars.
The DARWIN observatory is a future dark matter detector containing 40 tons of liquid xenon in an active volume of a dual-phase time projection chamber. An ultra low intrinsic radioactivity, large mass, low threshold and good energy resolution make DARWIN a suitable tool to perform a wide range of neutrino physics measurements. Natural xenon contains approximately 9% of ${}^{136}$Xe that is considered one of the primary candidates to undergo neutrinoless double beta decay, and thus shine the light on the mystery of neutrino mass origin. In the inner 5t fiducial volume, DARWIN is expected to have a background rate of less than 0.2 events / (t $\cdot$ yr) in the region of interest for neutrinoless double beta decay of ${}^{136}$Xe. This results in the projected half-life sensitivity of $2.4 \cdot 10^{27}$ yr after 10 years of operation. In addition, DARWIN will provide high precision measurements of solar neutrinos and can serve as a viable tool in an event of a galactic supernova. This contribution discusses key points that allow DARWIN to achieve such a sensitivity and its place among the next generation neutrino experiments.
When the 5 MW, 2.5 GeV, 1.3 ms proton pulses hit the ESSnuSB neutrino target there will be a copious production of not only neutrinos but also of muons. These muons could be used for precise neutrino cross-section measurements and sterile neutrino searches in a low energy nuSTORM facility and for high precision PMNS parameter measurements in a Neutrino Factory. An overview will be given of the design work that will be required to evaluate the technical challenges, the physics performances and the implementations of a nuSTORM facility and a Neutrino factory as possible future projects on the ESS site.
The intense beam of muon and electron neutrinos with precisely known energy distributions provided by the stored-muon facility (nuSTORM) shall allow for a rich physics program with considerable impact in our understanding of fundamental properties of neutrinos and their interactions. In particular, the precision goals of the oscillation program can only be achieved with a realistic modeling of neutrino-nucleus scattering dynamics. nuSTORM can critically contribute to this effort by providing the ultimate experimental program of neutrino-nucleus scattering measurements.
Especially appealing are the prospects for new precise direct or indirect measurement of neutrino scattering cross sections on single nucleons. They represent a priceless input for event generators and provide valuable information about hadron structure in the axial sector. Precise data in the kinematic region beyond the excitation of the Delta(1232) baryonic resonance will illuminate the poorly understood transition from resonant to deep-inelastic scattering, which is critical for the DUNE program.
The cross section for the scattering of neutrinos on complex nuclei arises as a non-trival interplay between lepton kinematic factors and response functions, which is very sensitive to the energy and momentum transferred to the target. The availability of charged-current interaction data with both muons and electrons in the final state under the same conditions can provide stringent tests of electroweak nuclear response theory. In particular, it is critical to pursue a better understanding of two-nucleon contributions to the cross section and the discrepancies with theory found by MINERvA and NOvA. No less relevant is the detailed description of various exclusive final states (including nucleon knockout, single and multiple pion and strangeness production) with direct implications for calorimetric neutrino-energy reconstruction at oscillation experiments.
Sensitivity to physics beyond the Standard Model (BSM) is provided by unique features of the nuSTORM design: the precisely known flavor composition and neutrino-energy spectrum. This allows exquisitely sensitive searches for short-baseline flavor transitions, covering topics such as light sterile neutrinos, nonstandard interactions, and non-unitarity of the neutrino mixing matrix.
In synergy with the goals of the neutrino-scattering program, new physics searches would also profit from measurements of exclusive final states. This would allow BSM neutrino interactions to be probed by means of precise measurements of neutrino-electron scattering, as well by searching for exotic final states, such as dileptons or single-photon signatures.
RES-NOVA is a new proposed experiment for the hunt of neutrinos from core-collapse supernovae (SN) via coherent elastic neutrino-nucleus scattering (CEvNS) using an array of archaeological Pb-based cryogenic detectors. The high CEvNS cross-section on Pb and the ultra-high radiopurity of archaeological Pb enable the operation of a high statistics experiment equally sensitive to all neutrino flavors. Thanks to these unique features, RES-NOVA will be as sensitive as super-size SN neutrino observatories, while running a detector with a total active volume of only (60 cm)$^3$. RES-NOVA will be able to reconstruct the SN neutrino parameters with great accuracy (at the 10% level) and it will be sensitive to SN bursts from the entire Milky Way Galaxy with 5 $\sigma$ statistical significance. During this workshop, the expected detector performance and sensitivity will be presented.
Annihilation of Weakly Interacting Massive Particles (WIMPs) in the center of the sun($\odot$), earth($\oplus$) and the galaxy can give rise to neutrino-antineutrino pairs as their final products. We look at the prospects of detecting such neutrinos at the proposed 50-kt Iron Calorimeter (ICAL) detector, to be housed at the upcoming India-Based Neutrino Observatory (INO), wherein the interaction of neutrinos ($\nu_{\mu}/\bar{\nu}_{\mu}$) with detector iron layers will produce $\mu^{-}/\mu^{+}$. The atmospheric neutrinos in GeV range will pose a serious background to such signal neutrinos, which fortunately, can be suppressed considerably by exploiting the excellent angular resolution of the ICAL detector. The expected sensitivity limits for 500 kt-years of ICAL exposure are quite competitive to other neutrino experiments for the WIMP masses $m_{\chi}$) $<$ 100 GeV. The expected 90 % C.L. exclusion sensitivity limits for 500 kt-years exposure for $\tau^{+} \tau^{-}$ channel (100 % branching ratio) for WIMP-nucleon Spin Dependent ($\sigma_{SD}$) and Spin Independent $\sigma_{SI}$) cross-section are found to be $\sigma_{SD,\odot} < 6.87\times 10^{-41}$ cm$^2$ and $\sigma_{SI,\odot} < 7.75\times 10^{-43}$ cm$^2$ for the WIMP mass ($m_{\chi}$) = 25 GeV, and $\sigma_{SI,\oplus} =1.02\times 10^{-44}~\mathrm{cm}^2$ for $m_{\chi}$ =52.14 GeV. For galactic centre searches, the expected 90 % C.L. sensitivity limits on velocity averaged annihilation cross-section $\langle\sigma_{A}v\rangle$ for a 30 GeV WIMP, assuming NFW WIMP profile and 100\% branching ratio for each channel are: $\langle\sigma_{A}v\rangle \leq 1.19\times 10^{-22}~ \mathrm{cm}^3 \mathrm{s}^{-1}$ for the $\mu^{+} \mu^{-}$ channel and \langle\sigma_{A}v\rangle \leq 6.35\times 10^{-23} \mathrm{cm}^3 \mathrm{s}^{-1}$ for the $\nu ~\bar{\nu}$ channel.
The Taishan Antineutrino Observatory (JUNO-TAO) is a satellite experiment of the JUNO detector. TAO consists of a ton-level liquid scintillator (LS) detector placed at ∼30 meters from a reactor core of the Taishan Nuclear Power Plant in Guangdong, China.
The main purposes of TAO are to provide a reference antineutrino spectrum for JUNO, removing possible model dependencies in the determination of the neutrino mass ordering, and to provide a benchmark measurement to test nuclear databases. The search for light sterile neutrinos around 1 eV will be another interesting physics opportunity. Moreover, precise inputs for nuclear physics and reliability tests of reactor monitor and safeguard will be obtained.
TAO is built around a Central Detector (CD) with 2.8 ton Gadolinium-doped LS (GdLS) contained in a spherical acrylic vessel of 1.8 m diameter. The event rate in the fiducial mass of ∼1 ton will be ∼2000 (∼4000) events/day considering (or not) the detection efficiency. About 4500 p.e./MeV are expected with an almost full coverage (∼10 m2) of SiPMs with >50% photon detection efficiency. The detector operates at -50◦C to lower the dark noise of SiPMs to ∼100 Hz/mm2. Considering the dark noise, cross talk, and charge resolution of the SiPMs, the expected energy resolution of TAO will be sub-percent in most of the relevant energy region.
The central detector is shielded by 1.2 m thick water tanks on the sides and 1 m High Density Polyethylene (HDPE) on the top. Cosmic muons will be detected in the water tanks equipped with PMTs and by Plastic Scintillator (PS) on the top.
The detector R&D started in 2018. A GdLS recipe has been developed and showed good transparency and light yield at -50◦C. The SiPMs and the readout electronics have been preliminarily tested at the same temperature. A prototype detector is being tested at -50◦C. The TAO experiment is expected to start operation in 2022. The status of the detector design, R&D and expected performances will be presented.
Dark photon is a well-motivated hypothetical particle introduced to explain BSM hints revealed in several independent experiments. A 3 kton-scale neutrino detector to be proposed in Yemilab, currently under construction in Korea can shed light on dark photon search using 100 MeV electron beam striking on a thick tungsten target. Best direct search sensitivity is expected for dark photons with a mass range from sub-MeV to O(10 MeV). In this talk, we will introduce a dark photon search using a deep underground neutrino detector at Yemilab.
We report recent results from the Reactor Experiment for Neutrino Oscillation (RENO). The RENO experiment consists of near and far detectors located at 294 and 1383 m, respectively, from the center of the six reactor cores of the Hanbit Nuclear Power Plant, Yonggwang, Korea. each reactor with maximum thermal output of 2.8 GWth. The reactor antineutrinos are detected through inverse beta decay interaction with free protons in gadolinium loaded hydrocarbon liquid scintillator as a target. In this presentation we will discuss about the updated measurement of \theta_{13} using 3000-days of RENO data, reactor antineutrino spectrum and its significance, anomalous spectral excess of reactor antineutrinos at 6\,MeV, and sub-eV and eV scale sterile neutrino searches.
Utilizing six powerful nuclear reactors as antineutrino sources and eight identically designed
underground detectors for a near-far relative measurement, the Daya Bay Reactor Neutrino
Experiment has achieved unprecedented precision in measuring the neutrino mixing angle 𝜃13 and
the neutrino mass squared difference |Δm2 |. With the largest sample of reactor antineutrino ee
interactions ever collected to date, Daya Bay has also performed a number of other measurements in neutrino physics, such as the determination of total reactor antineutrino flux and spectrum, the extraction of individual antineutrino flux and spectra of the two dominant isotopes (235U and 239Pu), as well as a search for sterile neutrino mixing, among others. In this talk, I will present the latest results from Daya Bay.
The Double Chooz (DC) multi-detector experiment is one of the reactor experiment measuring the ultimate θ13 mixing parameter exploiting one of the most powerful Nuclear Reactor in Europe, the EDF Chooz NPP located within the the LNCA underground laboratory facility in France. Due to the delay of the near detector and the shallow overburden, DC was forced to develop several novel techniques for active background reduction as well as one of the highest single detector precision so far, which combined with the multi-detector data period, provide a set of key measurements beyond the θ13 neutrino oscillations such as the world most precise reactor neutrino flux, often called the “mean-cross-section per fission”. In this talk, the DC collaboration will report the latest results of the experiment, include a forecast of its ultimate precision potential.
In our arXiv:2008.11280 (under publication), we demonstrate that the combined sensitivity of JUNO with NOvA and T2K experiments has the potential to become the first fully resolved (≥5σ) measurement of neutrino Mass Ordering (MO) tightly linked to the JUNO schedule. In the absence of any concrete MO theoretical prediction and given its intrinsic binary MO outcome, we thus highlight the benefits of having such a resolved measurement in the light of the remarkable MO resolution ability of the next generation of long baseline neutrino beams experiments, such as DUNE. We also motivate the opportunity of exploiting this MO experimental framework to scrutinise the standard oscillation model, thus, opening for unique discovery potential, should unexpected discrepancies manifest. Phenomenologically, the deepest insight relies on the articulation of MO resolved measurements via at least the two possible methodologies matter effects and purely vacuum oscillations. We argue and explain how the JUNO vacuum MO measurement may feasibly yield full resolution in combination to the next generation of long baseline neutrino beams experiments.
The ENUBET project aims at reducing the flux related systematics on a narrow band neutrino beam through the monitoring of the associated charged leptons in an instrumented decay tunnel.
A key element of the project is the design of a meson transfer line with conventional magnets that maximizes the yield of $K^+$ and $\pi^+$, while minimizing the total length to reduce meson decays in the not instrumented region. In order to limit particle rates on the tunnel instrumentation, a high level of beam collimation is needed, thus allowing undecayed mesons to reach the end of the tunnel. At the same time a fine tuning of the shielding and the collimators is required to minimize any beam induced background in the decay region. The transfer line is optimized with TRANSPORT and G4beamline simulations for 8.5 GeV/c mesons with a momentum bite of 10%, considering various proton drivers and target designs.
This contribution reports details on the current envisaged beamline with and improved proton target design. Highlights of a full GEANT4 simulation of the setup in terms of particle yields and expected neutrino fluxes at the far detector will be shown, together with doses estimation through a FLUKA simulation.
The Deep Underground Neutrino Experiment (DUNE) is the next generation long-baseline experiment for neutrino physics. DUNE will measure the oscillation probabilities of neutrinos and antineutrinos at unprecedented precision to quantify the Charge-Parity (CP) violation effects in the leptonic sector and shed light on the matter-antimatter asymmetry in the universe along with supernovae, solar neutrinos and beyond standard model searches.
An ambitious scientific programme for the largest LArTPC detectors ever built, such as the DUNE Far Detector (FD) modules, requires outstanding detector performance and measurement precision. In particular, the DUNE Ionization Laser System (IoLS) will provide independent fine-grained measurements of detector parameters and help diagnose the detector to achieve the needed spatial resolution and energy response of the detector.
In this talk, I will introduce the calibration needs for the DUNE-FD and provide an overview of the external calibration systems planned in order to achieve the physics goals of DUNE. I will briefly talk about the status of various calibration systems with a focus on the DUNE-IoLS and present the latest updates.
The precision measurement of neutrino parameters can be achieved by studying $\nu _\mu \to \nu_e$ oscillations over a large $L/E$ range. In the context of long baseline neutrino experiments (with fixed $L$), this amounts to examining oscillations over a wide energy range. Most of the current and future long baseline experiments such as Deep Underground neutrino experiment (DUNE) are mainly sensitive to the neighbourhood of first oscillation maximum of the $\nu_\mu \to \nu_e$ probability. In the present study, we elucidate the role of second oscillation maximum in investigating the sensitivity to the standard unknowns in oscillation physics. At the second oscillation maximum, one expects higher sensitivity to $\delta$ as the size of the $\delta$-dependent interference term is a factor of $\sim 3$ larger than that at the first oscillation maximum. We demonstrate that a beam tune optimized for coverage of the $2^{nd}$ oscillation maxima at DUNE is possible using proposed accelerator upgrades that provide multi-MW of power at proton energies of 8 GeV. We perform sensitivity studies in the context of DUNE by utilising this new multi-MW 8 GeV beam tune inaddition to wide-band beam tune that fully covers the region of the $1^{st}$ oscillation maxima and part of the $2^{nd}$. We highlight the importance of second oscillation maximum in deciphering the intrinsic CP phase and also explore its impact on the precision measurement of the CP phase. We find that addition of the $2^{nd}$ maxima beam tune to DUNE running with the standard wide-band CP optimized beam tune provides some improvement in sensitivity to the 3 flavor oscillation parameters. Further studies with improved detector resolution and beam optimizations will need to be carried out to fully exploit the capabilities of the $2^{nd}$ maxima beam options at DUNE.
The ND-GAr, or Near-Detector gaseous argon detector, is one of the proposed components of the future DUNE near detector complex. It has been designed to achieve low detection thresholds and high acceptance. The ND-GAr characteristics make it an optimal detector to study neutrino interactions which is crucial for measuring leptonic CP violation. In this talk the physics potential of the ND-GAr detector will be presented.
https://mediaspace.unipd.it/media/XIX+International+Workshop+on+Neutrino+Telescopes+- +Parallel+Room+2/1_k6kmopvj?st=7460&ed=7761
The Deep Underground Neutrino Experiment (DUNE) is a long-baseline neutrino oscillation experiment which utilizes liquid argon TPC technology. The far detector will be in Sanford Underground Research Facility (SURF) in South Dakota, USA. An external neutron source based on a DD (Deuterium-Deuterium) generator can be used to calibrate the detector parameters. The single-phase and dual-phase ProtoDUNE TPC detectors at CERN are used to test the two TPC technologies for DUNE. A DD generator was deployed at ProtoDUNE-SP (single phase) in July 2020 and data were collected. In this talk, I will show the neutron simulation in ProtoDUNE-SP detector. Low energy neutrons and their backgrounds are simulated and the analysis of signals resulting from interactions with liquid argon in the detector are presented.
Long-baseline neutrino experiments using megaton scale water Cerenkov far detectors can accumulate very large neutrino samples - $\mathcal{O}(10^3) \nu_e
\rm{/ year}$ - even with moderate beam intensity - $\mathcal{O}(100)$kW. The
presentation will show that at these intensities it is possible to instrument the beam with charged particle silicon pixel trackers to reconstruct precisely the energy, direction, initial flavour and chirality of the neutrino produced in each $\pi^{\pm} \to \mu^{\pm} \nu$ decay.
With proper synchronisation between these trackers and the far detector, the interacting neutrinos can be associated with the one reconstructed from the $\pi^{\pm} \to \mu^{\pm} \nu$ decay kinematics. The far detector is then only left with the identification of the oscillated neutrino flavour. This task is greatly simplified by the prior knowledge of the other neutrino properties.
In such a tagged long-baseline neutrino experiment, the individual tracking of each neutrino of the beam from production to detection greatly reduces systematic uncertainties. Added to that, the sub-percent energy resolution and the large neutrino sample size will allow to reach unprecedented precision on neutrino oscillation parameters. For instance the $\delta_{\rm{CP}}$ phase could be determined with a few degree precision across the whole $\delta_{\rm{CP}}$ range with 10 years of data of a long-baseline tagged neutrino experiment from U70 in Protvino, Russia, to a KM3NeT-ORCA like detector offshore Toulon, France.
More detailed studies will be performed with refined beam characteristics and detector layout.
The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator experiment currently under construction in the vicinity of the Pearl River Delta in Southern China. Its main focus lies on the determination of the Neutrino Mass Ordering via measuring the oscillated spectrum of electron anti-neutrinos from two nuclear power plants in 53 km distance each. JUNO requires to measure the prompt positron signal of the coincident inverse beta decay reaction used for the anti-neutrino detection with an unprecedented energy resolution of 3% at 1 MeV. To be able to achieve this challenging energy resolution, the scintillation volume is densely instrumented with 17,612 large 20''-PMT's and 25,600 small 3''-PMT's. In case of a particle interaction in the detector, the digitized electronic pulses from the readout electronics of the large PMT's will be recorded. From the reconstruction of these pulses, it is possible to obtain the number and detection times of PMT photon hits, which are then used to reconstruct the particle energy, the time and vertex of the light emission, and the particle type. This presentation will show the development status of the reconstruction algorithms in JUNO with the focus on low energy events from the reactor spectrum. These will include conventional approaches, as well as novel approaches using deep learning methods.
According to the baseline design of the 5 MW accelerator under construction in Lund, Sweden, its duty cycle will be only 4%, which leaves room for increasing the beam power and duty cycle to 10 MW and 8%, respectively. The linac power upgrade will be realized by increasing the linac pulse frequency from 14 to 28 Hz. The ESS linac pulse is 3 ms long which is too long for the cosmic ray-related neutrino background in the far detector and a 400 m circumference accumulator ring will be used to compress the beam pulse to 1.3 µs. A review will be given of the current results of the design and simulation work on the linac power upgrade and the pulse compressing accumulator ring
https://mediaspace.unipd.it/media/XIX+International+Workshop+on+Neutrino+Telescopes+- +Parallel+Room+2/1_k6kmopvj?st=9174&ed=9451
What if the dark matter content of the universe was made up of sterile neutrinos with a mass of the order of keV?
Currently, constraints from the measured relic abundance of dark matter and from observations in the X-ray band threaten the possibility of finding in terrestrial experiments a signal of such sterile neutrinos produced through oscillation and collisions in the early universe.
We consider two scenarios in which the simple hypothesis of
naturally relax these constraints and give new vigor to the hope of obtaining proof of the existence of these elusive dark matter candidates in experiments such as KATRIN and ECHo in the near future.
The purpose of the JSNS2 experiment is to search for sterile neutrinos with Δm2 near 1eV2. A 3 GeV J-PARC proton beam incident on a mercury target produces an intense neutrino beam from muon decay at rest which oscillates to anti-electron neutrinos. The JSNS2 detector is located at 24 m baseline from the target. The detector has a fiducial volume of 17 tons filled with GdLS, that efficiently can detect electron antineutrinos via the inverse beta decay reaction followed by a gamma signal from the captured neutron on Gd. The external gamma events induced by proton beam is one of the main backgrounds in sterile neutrino search. In this talk, we study beam related gamma background using MC simulation and the data taken in June 2020 and January 2021.
Liquid Argon Time Projection Chambers (LArTPCs) are an important technology in the field of experimental neutrino physics due to their exceptional calorimetric and position resolution capabilities. In particular, their ability to distinguish electrons from photons is crucial for current and future neutrino oscillation experiments. The MicroBooNE experiment is utilizing LArTPC technology to investigate the MiniBooNE low-energy excess, which could be either electron-like or photon-like in nature. To test the photon-like hypothesis, MicroBooNE is searching for single-photon events, a likely source of which is the neutral current (NC) $\Delta$ radiative decay. However, this search is complicated by the significantly more common neutrino-induced NC resonant $\pi^0$ production process. This talk presents the method for adapting the single-photon selection framework to select two-photon events which are characteristic of the NC $\pi^0$ topology. The NC $\pi^0$ selected sample is then used to constrain the systematic uncertainty on the NC $\Delta$ radiative decay measurement.
The J-PARC Sterile Neutrino Search at the J-PARC Spallation Neutron Source (JSNS2) experiment has started the search for neutrino oscillations with ∆m2 ~ 1 eV2 from anti-muon neutrino to Anti-electron neutron detected via the inverse beta decay (IBD) reaction which is tagged via gammas from neutron capture on Gadolinium. A 3 GeV 1 MW proton beam incident on a mercury target at the MLF at J-PARC produces an intense neutrino flux from muon decay at rest (mu-DAR). The JSNS2 experiment consists of a 50 tons liquid scintillator detector, that is already completed and located at a distance of 24m from the neutrino source. JSNS2 is the only experiment that can directly test the LSND anomaly without having to rely on theoretical scaling assumptions. The JSNS2 experiment successfully collected 10 days of data from the first physics run in June 2020 and second physics data taking has been started from Jan 2021. We have studied this accidental background using the physics run data. In this presentation, I will describe the cosmic ray induced background, which are dominant backgrounds that mimic a two independent IBD event signal.