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RICAP-2026 - Roma International Conference on AstroParticle Physics
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Europe/Rome
Chemistry Department, University Sapienza
Chemistry Department, University Sapienza
Piazzale Aldo Moro 2, 00185, Roma, Italy
Antonio Capone
(Istituto Nazionale di Fisica Nucleare)
Description
RICAP-2026 will be the 10th edition of the RICAP Conference. The acronym stands for Roma International Conference on Astro-Particle physics. The Conference, entirely dedicated to the study of high energy cosmic rays, traditionally has been organized by the INFN Sections and Physics Departments of Roma Universities “La Sapienza”, “Tor Vergata” and “Roma Tre”. The 10th edition of the Conference will be hosted by the Sapienza University of Roma. The aim of the Conference will be to present and discuss some of the most relevant theoretical and experimental results in the field of high energy cosmic radiations (gamma, neutrinos, charged cosmic rays). Special attention will be paid to the multi-messenger search for high energy cosmic rays sources, including gravitational wave searches. A special session will be dedicated to Dark Matter search and to low energy study of inherent neutrino properties. The Conference will give the opportunity to collect experimental results from presently operating experiments. Experiments in progress and future projects will be discussed, debating on different features and on sensitivities.
Previous editions:
RICAP – 2007, May 22nd–24th, INFN and University "La Sapienza", Roma
RICAP – 2009, May 20th–22nd, INFN and University "Tor Vergata", Roma
RICAP – 2011, May 25th 27th, INFN and University "Roma Tre", Roma
RICAP – 2013, May 22nd–24th, INFN and University La Sapienza, Roma
RICAP - 2014, September 30th-October 3rd, INFN-LNS, Noto
RICAP - 2016, September 5th-8th, Villa Tuscolana, Frascati, Roma
RICAP – 2018, September 4th-7th, INFN and University "Roma Tre", Roma
RICAP – 2022, September 6th-9th, INFN and University Sapienza, Roma
RICAP - 2024, September 23th-27th, Villa Tuscolana, Frascati, Roma
Secretariat: Francesca Paolucci and Elettra Perfetti
Registration
Registration Form
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Participants
150
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Registration
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Plenary: 1 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Chair Aldo Morselli
Convener: Prof. Antonio Capone (Istituto Nazionale di Fisica Nucleare)-
1
From Accelerated Particles to Cosmic Rays
The problem of the origin of cosmic rays is an elegant and yet complex concoction of pieces of physics that together describe how particles are energised in their accelerators, how these particles leave their sources (escape) and how their properties are shaped by transport on Galactic scales. I will summarize these aspects and their connection with the current and future observational situation, especially in the aftermath of LHAASO data.
Speaker: Pasquale Blasi (Istituto Nazionale di Fisica Nucleare) -
2
Telescope Array: current status and perspectives
The Telescope Array (TA) experiment is designed to investigate the origin and nature of ultra-high-energy cosmic rays (UHECRs) by observing the extensive air showers they produce in the Earth's atmosphere. The experiment employs complementary detection techniques, including a surface array of plastic scintillation detectors to sample secondary particles at ground level and fluorescence telescopes to observe the atmospheric fluorescence light emitted during air-shower development. These measurements enable studies of the cosmic-ray energy spectrum, mass composition, and arrival-direction distribution over the highest-energy regime accessible to direct observation.
During the past decade, the Telescope Array has produced a number of important results, including precise measurements of the energy spectrum, studies of the mass composition using both fluorescence and hybrid observations, and investigations of large-scale and intermediate-scale anisotropies. Continuous improvements in detector calibration, reconstruction techniques, and analysis methods have further enhanced the experiment's scientific capabilities.
This talk will present an overview of the Telescope Array experiment, highlight its most recent scientific results, and discuss the current status of the TAx4 expansion and other ongoing upgrades aimed at increasing the exposure and improving the sensitivity to the highest-energy cosmic rays. Future prospects, including continued observations and collaborative studies with other experiments, will also be presented.
Speaker: Yoshiki Tsunesada (Osaka Metropolitan University) -
3
Pierre Auger Observatory: current status and perspectives
Particles are accelerated in our Universe to energies exceeding 1e20 eV,
and a few of them reach the Earth. The Pierre Auger Observatory aims to
measure these rare ultra-high-energy cosmic rays using a detector
covering 3000 squared-km in La Pampa Amarilla, Argentina. Taking data
since 2004, the Observatory has delivered a significant amount of
high-quality data that has enabled advances in our understanding of the
origin of ultra-high-energy cosmic rays, the characterisation of
extensive air showers and hadronic interaction models, the search for
ultra-high-energy photons and neutrinos, and the observation and
modelling of atmospheric phenomena. In 2022, the Pierre Auger
Observatory began taking Phase II data with its upgraded, more sensitive
detector. I will present the main results from 20 years of operation and
discuss the future analysis prospects and the expected scientific
achievements with the upgradedSpeaker: Prof. Ioana Maris (Universite Libre de Bruxelles) -
4
The contribution of supernova remnants to the cosmic ray spectrum
While it is clear that supernova remnants accelerate particles up to very high energies, their actual contribution to the cosmic-ray spectrum remains uncertain. In recent years, very-high-energy gamma-ray observations of various Galactic sources- such as massive stars, microquasars, and other PeVatrons -have revealed the complex and intricate roles played by Galactic objects in the origin of cosmic rays. Clarifying the role of supernova remnants is an indispensable step toward unveiling the origin of Galactic cosmic rays. We discuss recent developments in particle acceleration at supernova remnants and highlight the main open problems.
Speaker: Pierre Cristofari (Observatoire de Paris)
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1
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12:30 PM
Lunch and registration
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Plenary: 2 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Chair Aldo Morselli
Convener: Prof. Emmanuel Moulin (CEA Saclay)-
5
Theoretical Aspects of Dark Matter Direct Detection
Direct detection experiments aim to observe dark matter particles in the Galactic halo through the tiny amounts of energy they may deposit in ultra-low-background underground detectors, producing observable signals such as nuclear recoils or electronic excitations.
Over the years, this experimental approach has been extended to an increasingly broad range of dark matter candidates, from multi-TeV weakly interacting massive particles (WIMPs) to sub-GeV dark matter, and even lighter particles that could be detected through their absorption in detector materials.
In this talk, I will review recent theoretical developments that underpin the interpretation of direct detection experiments. I will show how the prediction of observable signals across the broad landscape of dark matter candidates has evolved into a genuinely interdisciplinary endeavor, bringing together methods from particle physics, nuclear physics, condensed matter physics, and astrophysics.Speaker: Riccardo Catena (Chalmers University of Technology) -
6
Weak Signals, Strong Correlations: Dark Matter, Gamma Rays and the Large-Scale Structure of the Universe
Cross-correlations between gamma-ray emission and tracers of the large-scale structure provide a powerful approach to probe faint, diffuse signals in the high-energy sky. This talk will discuss how the spatial connection between unresolved gamma-ray backgrounds and the cosmic matter distribution can be used to disentangle astrophysical contributions from potential signatures of dark matter. I will outline the key methodology, highlight recent results, and discuss the prospects of multi-wavelength and multi-tracer analyses for improving our understanding of the gamma-ray Universe.
Speaker: Nicolao Fornengo (University of Torino and INFN/Torino) -
7
Indirect Search for Dark Matter
The existence of a dark, non-baryonic and non-relativistic component constituting a large fraction ($\sim$85%) of the matter density of the Universe is widely accepted in modern astrophysics, thanks to several indirect but compelling pieces of astronomical evidence. Such a component is usually called dark matter (DM), and likely consists of one or several so-far undetected particles hypothesized in theories beyond the Standard Model (SM). Unveiling the nature of DM is a paramount issue of both modern fundamental physics and astrophysics. Two particularly well-motivated classes of DM candidates are represented by weakly interacting massive particles (WIMPs) and axions or axion-like particles (ALPs). WIMPs naturally arise in many SM extensions, have a mass in the range between $\mathcal{O}$(10) GeV and $\mathcal{O}$(100) TeV and interaction cross section values typical of the electroweak scale ($\sim$10$^{-26}$ cm$^3$ s$^{-1}$). On the other hand, ALPs are hypothesized to explain the non-violation of fundamental symmetries in strong interactions, have masses below 0.01 eV and are supposed to weakly couple to electromagnetic fields. One of the most promising approaches to shed light on WIMPs is to search for signatures of DM annihilation or decay into SM particles from regions of the sky believed to be highly DM dominated, such as the Galactic Center, the clusters of galaxies, and the dwarf spheroidal galaxies (dSphs) of the Milky Way; indeed, among the final DM annihilation or decay states, a flux of gamma rays produced by the subsequent annihilation of DM-generated SM particle pairs is expected at energies up to the DM mass, which could be detected by space- and ground-based gamma-ray instruments. In this context, dSphs are among the most promising observational targets, due to their relative proximity and lack of astrophysical gamma-ray background sources. The search for ALPs in gamma-ray astronomy relies instead on the study of spectral oscillations that they produce in the spectra of powerful gamma-ray emitters, such as blazars. In this contribution, I will review the current status and future prospects of the indirect DM searches in the very-high energy gamma-ray regime with current and next-generation instruments, discussing the systematic uncertainties that affect the detection of such signals.
Speaker: Francesco Gabriele Saturni -
8
Indirect Dark Matter Searches with IceCube: Recent Results and Prospects
Dark matter particles can accumulate in astrophysical objects—such as the Galactic Center, the Sun, the Earth, and other galaxies—where they may self-annihilate or decay into Standard Model particles, producing an anomalous neutrino flux detectable at Earth. The IceCube Neutrino Observatory, a cubic-kilometer Cherenkov detector embedded in the glacial ice at the South Pole, provides a unique window onto indirect searches for such dark matter signals through high-energy neutrinos. This talk presents IceCube's most recent results from these searches, including updated constraints across a broad range of dark matter masses and theoretical models. We also present the prospects opened up by the recently deployed IceCube Upgrade, whose improved performance in the GeV regime is expected to enhance sensitivity to dark matter signals in the coming years.
Speaker: Nhan Chau (Université libre de Bruxelles)
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5
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3:30 PM
coffee break
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Plenary: 3 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Chair Aldo Morselli
Convener: Prof. Irene Di Palma (Istituto Nazionale di Fisica Nucleare)-
9
LISA: Opening the Low-Frequency Gravitational-Wave Window from Space
The Laser Interferometer Space Antenna (LISA), the first space-based gravitational-wave observatory, is currently under development and is scheduled for launch in 2035.
Its aim is to open the low-frequency gravitational-wave window, spanning the 0.1 mHz to 1 Hz band, which is inaccessible to ground-based detectors because of Newtonian noise and can only be explored from space.
By targeting this unexplored frequency range, LISA will enable observations of massive black-hole mergers, extreme mass-ratio inspirals, compact Galactic binaries, and potentially new cosmological and fundamental-physics phenomena.
This presentation will provide an overview of the current status of the mission, its scientific objectives, its principle of operation, and the challenging features of the LISA instrument.Speaker: Prof. Rita Dolesi (Università di Trento) -
10
Follow-up of LVK O4 Gravitational Wave events with MAGIC and LST-1: Constraints on GW VHE Gamma-Ray Counterparts
We present very high-energy (E > 100 GeV) gamma-ray observations of GW240615 and S241125n, two particularly well-localized and astrophysically compelling Gravitational Wave (GW) events detected by LIGO-Virgo-KAGRA (LVK) during the O4b observing run. These events were followed up jointly with the Major Atmospheric Gamma-Ray Imaging Cherenkov Telescope (MAGIC) and Large-Sized Telescope (LST-1) telescopes at the Roque de los Muchachos Observatory in La Palma, Spain. We also developed a statistical method to compute a unique global Upper Limit (UL) on the gamma-ray flux for sources with large localization uncertainties.
The first event, GW240615, is the best-localized GW event to date. It was observed 15 hours after the alert under high zenith angles and elevated Night Sky Background. Using our developed method, we derived a sky map of ULs alongside a global UL, reaching energies down to 0.15 TeV.
The second event, S241125n, was notable for an X-ray counterpart candidate detected by Swift/GUANO and the Einstein Probe. Observations were taken 19 hours after the LVK alert. To account for suboptimal, cloudy weather conditions, we applied LIDAR-based atmospheric corrections and dedicated Monte Carlo simulations to perform a robust analysis, placing ULs on the gamma-ray emission above 0.6 TeV.
While these events did not result in any detection, our results constrain gamma-ray emission models for binary black hole mergers, combining them with other constraints allowing for a multi-messenger analysis. We evaluate the observations against theoretical scenarios to constrain the mechanisms of potential gamma-ray production in binary black hole systems.
(Note: This work is accepted for publishing at PASP and is anticipated to be published by the time of the conference.)
Speaker: Juan Jiménez Quiles (IFAE (Institut de Física d'Altes Energies)) -
11
Phsyics and Astrophysics of LVK, the network of GW detectors on the Earth
In this talk, we will present some of the latest results obtained with the global network of ground-based gravitational-wave interferometers. We will discuss the impact of gravitational-wave observations on testing Einstein's theory of General Relativity and highlight the emerging features of the black hole population inferred from recent detections. Finally, we will illustrate how gravitational-wave observations are opening new avenues for cosmology, providing independent probes of the expansion history and large-scale properties of the Universe.
Speaker: Fulvio Ricci (Istituto Nazionale di Fisica Nucleare) -
12
The Einstein Telescope: Approaching the Start-Up Phase
The ET detector configuration is not yet fully finalized, and crucial decisions must still be taken. However, supported by scientific cost-benefit analyses, the development of two primary configurations has been actively pursued and is now in an advanced state. This presentation provides an updated overview summarizing the major challenges that have emerged since the establishment of the ET Collaboration, alongside the measures envisaged to tackle them.
Speaker: Ettore Majorana (Istituto Nazionale di Fisica Nucleare)
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9
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Poster session: 2’ poster’s flash presentations
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Plenary: 4 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Chair Aldo Morselli
Convener: Aldo Morselli (Istituto Nazionale di Fisica Nucleare)-
13
Fermi's past, present and future.
Now in its eighteenth year of operation, the Fermi Gamma-ray Space Telescope continues to survey the entire sky every three hours across more than seven decades of energy, from ~8 keV with the Gamma-ray Burst Monitor (GBM) to beyond 300 GeV with the Large Area Telescope (LAT). Both instruments remain healthy as shown by recent achievements including new discoveries and catalogs of sources and transients. Looking ahead, Fermi's uninterrupted long-baseline coverage positions it as a cornerstone of the multimessenger era, complementing new-generation facilities and enabling continued discovery well into the next decade. In this talk I will provide an overview of the biggest achievements, recent discoveries, and a hint into the future perspectives of the mission.
Speaker: Michela Negro -
14
The MAGIC of Very-High-Energy Gamma-Ray Astronomy: Status and Recent Highlights
Instrumentation for gamma-ray astronomy has advanced tremendously over the past two decades. The study of the Universe's most violent environments has opened a unique window into the frontiers of physics, allowing researchers to explore processes that are impossible to replicate in Earth-based laboratories. At the forefront of ground-based gamma-ray astronomy is the MAGIC (Major Atmospheric Gamma Imaging Cherenkov) stereoscopic system. Located at 2,200 m a.s.l. on the Canary Island of La Palma, Spain. MAGIC started operating with its first telescope in 2003 and, since 2009, has operated in stereo mode with its two 17-meter-diameter mirror telescopes.
As a world-leading instrument for observations in the energy range from 20 GeV to over 100 TeV, MAGIC is a key contributor to global multi-wavelength and multi-messenger campaigns. In this presentation, I will provide a status report on the MAGIC facility and highlight scientific results across various topics, from conventional astrophysics—such as Gamma-Ray Bursts, Active Galactic Nuclei, and Cosmic Rays—to fundamental physics, such as searches for Dark Matter. Finally, I will discuss the technical and observational prospects for the near future, including joint scientific exploitation and synergies with the co-located CTAO-North LST subarray.
Speaker: David Paneque (Max Planck Institute for Physics) -
15
H.E.S.S. highlights and perspectives
The High Energy Stereoscopic System (H.E.S.S.) iss an array of five imaging atmospheric Cherenkov telescopes located in the Khomas Highlands of Namibia to study gamma-ray emission in the energy range from a few ten GeV up to several ten TeV. Started more than 20 years ago, stereoscopic observations provide an unprecedented view of a diversity of astrophysical objects, from pulsars, supernova remnants, microquasars in the Milky Way to active galactic nuclei and gamma-ray bursts at cosmological distances. Located in the Southern hemisphere, H.E.S.S. allows for unique observations the Galactic centre region.
I will present the status of the H.E.S.S. observatory and discuss its latest highlights from observations of microquasars, pulsars, the base of the Fermi Bubbles, the Galactic plane survey, GRBs and gravitational wave follow-ups, together the latest results on dark matter and axion-like particle searches.Speaker: Emmanuel Moulin (CEA Saclay)
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13
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10:30 AM
Coffee Break
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Plenary: 5 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Chair Aldo Morselli
Convener: Prof. Dafne Guetta (Ariel University, Ariel)-
16
Status of the CTAO LST Project
The Large-Sized Telescope (LST) Array is the flagship instrument of the Cherenkov Telescope Array Observatory (CTAO) at the lowest gamma-ray energies, bridging the gap between satellite- and ground-based observations. With its unprecedented sensitivity below 1TeV, rapid slewing capability, and large collection area, the LST Array is designed to explore the dynamic high-energy Universe, enabling transformative studies of gamma-ray bursts, active galactic nuclei, pulsars, Galactic particle accelerators, dark matter, and multi-messenger transients.
The LST project has now approached a historic milestone with the completion of the four-telescope array at the CTAO Northern site on La Palma. Building upon the remarkable scientific success of LST-1, which has been in operation since 2020 and has already demonstrated the unique capabilities of the LST concept through a broad range of scientific discoveries, the completed array marks the beginning of a new era in very-high-energy gamma-ray astronomy. The stereoscopic LST Array will provide a substantial leap in sensitivity, angular resolution, and energy reconstruction at the lowest energies accessible from the ground, significantly expanding the discovery space for both transient and persistent cosmic accelerators.
This presentation reviews the current status of the LST project, including the completion of the array and recent commissioning progress. Particular emphasis will be placed on the scientific opportunities opened by the full LST Array, its central role in the global multi-messenger and time-domain astronomy network, and its contribution to addressing some of the most compelling questions in high-energy astrophysics and fundamental physics.Speaker: Masahiro Teshima -
17
Highlights on recent VHE observations of the extragalactic sky
Active galactic nuclei (AGN), particularly blazars, dominate the extragalactic very-high-energy (VHE; E > 100 GeV) gamma-ray sky. These sources host relativistic jets capable of accelerating particles to extreme energies, producing non-thermal emission observed from radio frequencies up to the TeV regime. Despite decades of observations, the physical processes responsible for particle acceleration and high-energy emission in these systems remain only partially understood. Their strong variability across all wavelengths and their complex behaviour further complicate the interpretation of the underlying mechanisms and jet environments.
In this talk, I will present recent studies of gamma-ray blazars performed with the MAGIC and LST-1 telescopes. I will highlight how VHE observations, combined with coordinated multi-wavelength campaigns from radio to X-rays and GeV gamma rays, provide crucial insight into the structure and dynamics of relativistic jets, the location of the emitting regions, and the dominant particle acceleration and radiation processes. These results demonstrate the key role of current and next-generation Cherenkov telescopes in advancing our understanding of the most extreme persistent accelerators in the Universe.
Speaker: Jorge Otero Santos (Istituto Nazionale di Fisica Nucleare) -
18
Unveiling the High-Energy Gamma-ray Nature of Gamma-Loud Protostars
The earliest stages of star formation are typically associated with the cold, dark, and thermal environments of dense molecular clouds. However, emerging evidence suggests these stellar nurseries are also sites of intense non-thermal activity. While radio observations have previously hinted at the presence of relativistic electrons in protostellar jets, direct evidence of proton acceleration has remained elusive until now.
In this talk, I will present our recent statistical detection of γ-rays from a population of young stellar objects, introducing a newly identified Galactic class: Gamma-Loud Protostars. I will outline the observational evidence pointing toward particle acceleration within protostellar jets, where γ-ray emission is driven by protons interacting with the surrounding molecular clouds via pion decay.
We will also explore a key correlation found between cosmic-ray output and bolometric luminosity, demonstrating that this particle acceleration scales directly with the mechanical power of the system. Finally, I will discuss what this previously overlooked high-energy emission means for our broader understanding of star formation, and how this energetic feedback shapes the immediate environment for subsequent star and planet formation.Speaker: Ruben Lopez Coto (IAA-CSIC, Glorieta de la Astronomía s/n, 18008, Granada) -
19
Probing Gamma-ray Emission in AGNs with the EHT and Multiwavelength Observations
The origin and emission mechanisms responsible for the gamma-ray emission from supermassive black holes and their relativistic jets remain among the major open questions in high-energy astrophysics. The Event Horizon Telescope (EHT) has enabled horizon-scale observations of active galactic nuclei (AGNs) with unprecedented angular resolution, providing a unique opportunity to connect the physical conditions near the black hole with the acceleration of high-energy particles. In parallel with the EHT observations, extensive quasi-simultaneous multiwavelength (MWL) campaigns were carried out using ground- and space-based observatories, spanning the electromagnetic spectrum from radio wavelengths to TeV gamma rays.
In this talk, I will focus on two archetypal AGNs exhibiting bright and highly variable gamma-ray emission: the radio galaxy M87, the first black hole ever imaged by the EHT, and the blazar 3C 279. I will present key results from the first two EHT-MWL campaigns, including the detection of high-energy and very-high-energy gamma-ray flaring episodes and their interpretation through broadband MWL modeling. These coordinated observations provide new insights on the origin of the gamma-ray emission and on the mechanisms responsible for particle acceleration in relativistic jets.Speaker: Giacomo Principe (Istituto Nazionale di Fisica Nucleare)
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16
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1:00 PM
Lunch break
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High Energy Cosmic Rays: 1 Aula A
Aula A
Chemistry Department, University Sapienza
Conveners: Joerg Hoerandel (Radboud University Nijmegen), Valerio Verzi (Istituto Nazionale di Fisica Nucleare)-
20
Study of ultra-high-energy cosmic rays with fully-sky coverage using the Pierre Auger Observatory and the Telescope Array
Despite decades of observations, the origin of ultra-high-energy cosmic rays (UHECRs) remains unknown. Because UHECRs are charged particles, they are deflected by extragalactic and Galactic magnetic fields during their propagation, making a direct association with their sources hard to determine. The discovery of a dipole anisotropy in the arrival direction of UHECRs with energies above 8 EeV towards a direction far away from the Galactic Center was reported by the Pierre Auger Collaboration, proving the extragalactic origin of UHECRs, but no evidence of smaller-scale anisotropies at a statistically significant level has been found so far. Full-sky coverage can only be achieved by combining data from the Pierre Auger Observatory and the Telescope Array. This joint dataset enables anisotropy studies over the entire celestial sphere, allowing analyses that cannot be performed with the incomplete sky coverage of either observatory alone. In this contribution, we review the main results obtained with the combined datasets with events detected until December 2022 at the Pierre Auger Observatory and until May 2024 at the Telescope Array, and provide an outlook for future research.
Speaker: Marta Bianciotto -
21
Multi-Messenger Concordance for the Cygnus Region as the Source of the Cosmic-Ray Knee
The origin of the cosmic-ray (CR) knee remains one of the central open questions in particle astrophysics. Recent measurements by the Large High Altitude Air Shower Observatory revealed a pronounced feature in the proton spectrum at 3-4 PeV, while observations of diffuse gamma rays above 100 TeV do not exhibit a corresponding spectral break. This apparent discrepancy challenges the standard interpretation, in which the local CR distribution is representative of the Galactic CR sea. Here, we investigate whether the CR knee can instead originate from the Cygnus region as a nearby PeVatron. By combining CR measurements at Earth with very-high-energy gamma-ray observations from LHAASO and the Tibet-ASγ experiment, we identify an additional hard gamma-ray component in the inner Galaxy consistent with a source located in the Cygnus region. We show that our results provide a concordance multimessenger picture. The required properties are compatible with the PeVatron candidate detected by LHAASO in the Cygnus bubble and with the Galactic neutrino flux observed by the IceCube Neutrino Observatory.
Speaker: Francesco Lorenzo Villante (Istituto Nazionale di Fisica Nucleare) -
22
Particle Acceleration in Choked Jets from Blue and Red Supergiants with relativistic MHD simulations
The collapse of massive stars is often accompanied by the formation of accreting compact objects that launch relativistic jets. While some of these jets successfully emerge from the stellar envelope and power gamma-ray bursts, others fail to break out and become choked within the progenitor star.
Even in the absence of successful jet emergence, these systems can still produce observable emission through the dissipation of jet energy into a hot, pressurised cocoon, which expands through the stellar envelope and eventually breaks out as a mildly relativistic outflow.We investigate the plasma physics of massive collapsing stars hosting choked jets through relativistic, non-radiative, and non-resistive MHD simulations.
We identify the regions of parameter space that lead to jet choking and, for these configurations, study the role of the resulting strong shocks in particle acceleration processes. Our analysis is performed for a range of red and blue supergiant progenitors, highlighting the impact of stellar structure on jet evolution and shock properties.Speaker: Matteo Pais (Istituto Nazionale di Fisica Nucleare) -
23
Detection of non-thermal X-ray emission at the region of SNR gamma-Cygni
The SNR gamma-Cygni region is an important target for studying cosmic-ray acceleration because gamma-ray instruments have identified MeV, GeV, and TeV sources. However, no previous X-ray study has covered the entire SNR for both the soft and hard energy bands (i.e., 0.5-7 keV), and the CR accelerators to the TeV sources were not clear. In this talk, I will present the continuous X-ray scan to the entire SNR "gamma-Cygni" and its vicinity with Swift-XRT. We performed X-ray spectra fitting to separate the thermal and non-thermal X-ray components from the SNR and study its physical properties. We found significant non-thermal X-ray counterparts for TeV sources: MAGIC J2019+408 and 1LHAASO J2020+4034 (KM2A). Our spectral energy distribution (SED) analysis on these sources reveals the CR acceleration mechanisms in this region. Our novel method can scan extended sources with Swift-XRT and study the physical processes beyond the X-ray telescopes' field of view. This will be very important for studying TeV/PeV gamma-ray sources, especially in the era of high resolution Imaging air Cherenkov telescopes (IACTs).
Speaker: Dr Heshou Zhang (INAF - OA Brera)
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20
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Indirect Dark Matter detection: 1 Aula C
Aula C
Chemistry Department, University Sapienza
Conveners: Emmanuel Moulin (CEA Saclay), Federica Giacchino (Istituto Nazionale di Fisica Nucleare)-
24
Dark matter searches in very-high-energy photons
A unique probe for searching for dark matter (DM) signals is through their indirect detection by observing the sky with detectors sensitive over the GeV – PeV energy range. Following the path of photons in the mentioned energy range coming from the Universe and interacting with the Earth's atmosphere, this talk will showcase a selection of results on indirect DM searches with satellite experiments, water Cherenkov detectors, and imaging atmospheric Cherenkov telescopes. The discussion will conclude with prospects on DM searches from the coming generation of instruments.
Speaker: Alessandro Montanari (Laboratoire Leprince-Ringuet, Ecole Polytechnique (UMR 7638, CNRS/IN2P3, Institut Polytechnique de Paris)) -
25
Astrophysical ALP searches from ground and space
Axion-like particles (ALPs) are very light, neutral spin-zero bosons predicted by superstring theory, which primarily couple to two photons. In cosmic environments, their interaction with external magnetic fields triggers two main physical phenomena: (i) photon-ALP oscillations, and (ii) modifications of the photon polarization state. This talk reviews how these effects can be uniquely probed through a complementary approach involving both ground-based and space-borne observatories. On the one hand, ground-based very-high-energy gamma-ray detectors like LHAASO, ASTRI, and the upcoming CTAO hunt for photon-ALP oscillations, which are expected to alter cosmic transparency and introduce spectral irregularities. On the other hand, space missions provide a multi-messenger window into ALP physics across a wide energy range. This includes both constraints on photon-ALP mixing derived from high-energy spectral features with current gamma-ray space telescopes like Fermi-LAT, and searches for polarization signatures. For the latter, we highlight how current X-ray polarimeters like IXPE, alongside the upcoming MeV instrument COSI and future concepts like AMEGO, can detect ALP-induced polarization features. Together, this dual ground-and-space perspective offers a powerful path to either discover ALPs or significantly constrain their parameter space.
Speaker: Giorgio Galanti (INAF, IASF-Milano) -
26
Deeper analysis of FermiLAT unassociated 4FGL J2112.5-3043 for possible identification
Unidentified gamma-ray sources in the Fermi-LAT catalog represent a key target for astroparticle studies, as they may host either conventional compact objects or more exotic scenarios such as dark matter (DM) subhalos. We present a detailed gamma-ray and multiwavelength investigation of 4FGL J2112.5−3043, a high-significance LAT source with no firmly established counterpart to date.
Using Fermi-LAT data, we perform a comprehensive spectral and spatial analysis. The emission is consistent with a point-like morphology, exhibits no significant flux variability, and is best described by a sub-exponential cutoff power-law spectrum. We complement the gamma-ray characterization with a dedicated multiwavelength search aimed at constraining possible astrophysical counterparts.
We discuss the results in the context of both a pulsar interpretation and DM annihilation in a nearby Galactic subhalo. While no definitive identification can be reached, the combined spectral and multiwavelength analysis provides valuable constraints on both scenarios, highlighting 4FGL J2112.5−3043 as a compelling target for future observations and astroparticle and multimessenger investigations.
Speaker: Federica Giacchino (Istituto Nazionale di Fisica Nucleare) -
27
Is the spherical profile enough for gamma-ray dark matter indirect searches?
Recent results from Galactic surveys, such as Gaia, and from hydrodynamical cold dark matter simulations of Milky Way-like galaxies have shown that the galactic dark matter halo likely deviates from spherical symmetry. Its shape and orientation may constitute an additional significant source of uncertainty for indirect dark matter searches. In this work we develop a fast and light computational tool that accommodates different analytical density profiles, triaxial halo shapes and arbitrary halo orientations, and predicts the corresponding gamma-ray flux maps as observed from Earth. We explore the parameter space of a triaxial Galactic dark matter halo with the aim of assessing which configurations are degenerate with, or clearly distinguishable from, the spherical case. The comparison is carried out at the level of the projected two-dimensional gamma-ray flux map of the inner Galactic region rather than at the level of the three-dimensional density distribution, taking into account the sensitivity of the Fermi-LAT telescope as well as the presence of Galactic diffuse emission.
Speaker: Margherita Scuderi (Sorbonne University & LPTHE, CNRS, France) -
28
Constraints on Axion-Like Particles from Ten Years of Blazar Observations with MAGIC and LST-1
Axion-like particles (ALPs) are well-motivated extensions of the Standard Model that can induce photon–ALP oscillations in the presence of external magnetic fields. For very-high-energy (VHE) gamma rays, these oscillations may leave observable signatures in the spectra of astrophysical sources, such as energy-dependent flux fluctuations or spectral hardening at TeV energies.
We present a comprehensive search for ALP-induced effects using observations of four blazars (Mrk421, Mrk501, BL Lac and 1ES 1959+650, for a total of more than 900 hours) collected over a decade (2014–2024) with the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes and the first Large-Sized Telescope (LST-1) of the Cherenkov Telescope Array Observatory (CTAO). Their broad energy coverage and energy resolution make them particularly well suited to resolve the spectral features expected from photon–ALP oscillations.
Using a Bayesian block analysis, we identify periods of approximately steady VHE emission and construct homogeneous data subsets for the ALP search. For each source, we model photon–ALP conversions occurring within the blazar jet and in the Galactic magnetic field and compute the corresponding photon survival probability. We further develop a modular statistical framework that combines multiple datasets, sources, and instruments directly at the likelihood level, maximizing the sensitivity to a common ALP signal.
No statistically significant evidence is found for ALP-induced phenomena in the VHE emission from the analyzed blazars. We therefore derive upper limits on the ALP–photon coupling strength over the ALP mass range of 1 to 1000 neV, demonstrating the potential of joint multi-source and multi-instrument analyses to probe the ALP parameter space with current and next-generation Cherenkov telescopes.
Speaker: Francesco Schiavone (Università degli Studi di Bari & INFN Bari)
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24
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Searches for Galactic sources: 1 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Conveners: Sabrina Casanova (Ruhr Universitaet Bochum), Silvia Celli (Istituto Nazionale di Fisica Nucleare)-
29
Gamma rays from Galactic clouds
The interactions of cosmic rays (CRs) with the gas of the interstellar medium provide direct insights into the spatial and spectral distribution of these relativistic particles that can be used to derive information about the CR source distribution, propagation, and penetration into dense regions. The study of molecular clouds (MCs) -or in general of any gas portion- allows us to make a discrete mapping of Galactic CRs on the scale of the cloud sizes, ~10-100 pc.
Here I will review the recent results derived from Fermi-LAT analysis of data collected in the direction of MCs located throughout the Milky Way. I will give special emphasis to new results derived from the analysis of ~70 MCs localized within 2 kpc from us. Recent analysis of dust extinction, combined with Gaia parallax measurements provide an improved localization of these gas regions with an unprecedentedly high accuracy allowing us to make a precise tomography of CRs in the local medium. I will discuss the results in the context of acceleration and propagation of low-energy cosmic rays in dense environments, and give some prospects for future studies that could be carried out with next generation facilities, especially with LHAASO and CTAO.
Speaker: Giada Peron (INAF-OAA) -
30
Microquasar detections with LHAASO
The origin of high-energy cosmic rays remains a long-standing question in astro-particle physics. With the operation of detectors at UHE (>100 TeV) energy range, accumulating observational evidence indicates that microquasars may represent a new class of powerful particle accelerators and contribute to the high-energy cosmic rays in our Galaxy. LHAASO has detected UHE gamma-ray emissions surrounding multiple microquasars, implying that it is common for particle acceleration in their external jets. Furthermore, the unambiguous detection of the well-known and long-debated binary system Cygnus X-3 verifies that microquasar is capable of accelerating particles to tens of PeV during its flaring period. In this talk, I will briefly present the latest progress on detection of microquasars by LHAASO.
Speaker: Cong Li -
31
Constraints on Hadronic Emission from Microquasars Detected by LHAASO
Recently, the Large High-Altitude Air Shower Observatory (LHAASO) collaboration reported ultra-high-energy gamma rays from six microquasar systems.
For five of these sources, the emission exceeds $100$ TeV, making microquasars promising Galactic PeVatrons.
In this work, we investigate whether gamma-rays around $100$ TeV originate from hadronic interactions of accelerated cosmic rays with the ambient medium and estimate the contribution of these sources to the CR proton spectrum.
We consider a cosmic-ray transport scenario in which particle propagation in the source vicinity is diffusion-dominated, with a diffusion coefficient largely suppressed with respect to the average Galactic value. At large distances from the source, the diffusion coefficient matches the Galactic value. We assume continuous injection over timescales of $t_{\rm age}=0.1-1$ Myrs.
Using available measurements of the gas density in the emission regions, we find that hadronic interactions alone cannot fully account for the observed emission in any of the detected sources, allowing us to place upper limits on the hadronic contribution to the observed gamma-ray flux.
We then estimate the contribution of these systems to the Galactic CR proton spectrum and show that it strongly depends on the source age and injection history.Speaker: Vittoria Vecchiotti (INAF-OAA) -
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The millisecond pulsar contribution to the cosmic-ray positron spectrum
Millisecond pulsars (MSPs) constitute a peculiar subset of the Galactic pulsar population. Having evolved beyond their spin-down phase, they are old pulsars that have been "recycled", or spun-up by accretion of the matter of a companion star. They are characterised by very short rotation periods, ages significantly greater and magnetic fields lower than those of non-recycled pulsars, and they exhibit an approximately constant luminosity over time, typically lower than that of younger pulsars with ages below ~1 Myr. Gamma-ray observations indicate that MSPs are capable of accelerating leptons in their surroundings, which can then escape and propagate through the Galaxy but the maximum energy to which MSPs can accelerate leptons is still unclear. The old MSPs are expected to easily release particles in the ISM whereas younger pulsars are found amid PWNe and SNRs where particles might get trapped.
By assuming a Galactic MSP birth rate, an average constant luminosity for the population and a lepton injection efficiency, one can estimate the total energy density of positrons in the Galaxy contributed by this class of sources. This energy density exceeds that of cosmic-ray positrons measured at Earth above ~10 GeV, suggesting that MSPs may account for at least a fraction of the positron energy density.
We model the cosmic-ray injection at MSPs and solve the transport equation from the pulsars to the Earth with the Green functions formalism. We present an assessment of the contribution of known MSPs from the ATNF catalogue to the local positron flux and evaluate the impact of physical parameters such as the maximum energy of the leptons injected into the ISM by the MSPs.
Speaker: Lioni-Moana Bourguinat (Gran Sasso Science Institute (GSSI, Italy)) -
33
The Milky Way at TeV Energies: the H.E.S.S. Galactic Plane Survey
The High Energy Stereoscopic System (H.E.S.S.) continues to be the only instrument at very high energies in the Southern hemisphere. The H.E.S.S. Galactic Plane Survey (HGPS) makes use of the ideal viewing conditions on the Galactic plane, providing a rich data set of survey and in-depth observations. Recent data and in particular reanalyses of the extensive archive compiled during over two decades of operation, combined with sophisticated new analysis frameworks, enables us to study the substantial variety of sources of different classes as well as diffuse emission in the Galactic plane.
In this presentation I will present the status of the systematic exploitation of the HGPS data, including the second H.E.S.S. catalogue of Galactic sources, population studies via population synthesis, and the prospects for diffuse-emission measurements.Speaker: Kathrin Egberts (Universität Potsdam)
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29
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3:45 PM
Coffee Break
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High Energy Cosmic Rays: 2 Aula A
Aula A
Chemistry Department, University Sapienza
Conveners: Joerg Hoerandel (Radboud University Nijmegen), Valerio Verzi (Istituto Nazionale di Fisica Nucleare)-
34
Constraining The Physics Beyond the Standard Model with the Pierre Auger Observatory
The Pierre Auger Observatory is the world’s largest cosmic-ray detector, covering an area of approximately (3000 Km^2). It investigates the most energetic cosmic rays reaching Earth by detecting the extensive air showers produced during their propagation through the atmosphere. Thanks to its unprecedented exposure and precision, the Observatory provides leading measurements of cosmic rays at energies above 0.1 EeV. The extreme energies probed by the Pierre Auger Observatory provide a unique opportunity to test fundamental physics well beyond the energy scales directly accessible to terrestrial particle accelerators, placing the experiment at the forefront of multi-messenger and astroparticle physics. This contribution reviews how Pierre Auger Observatory data can be used to constrain scenarios beyond the Standard Model, with particular emphasis on superheavy dark-matter decay and violations of Lorentz invariance. Current constraints on these exotic scenarios will be presented, together with the prospects for improved sensitivity offered by future analyses and by the ongoing upgrade of the Observatory.
Speaker: Antonio Ambrosone (Istituto Nazionale di Fisica Nucleare) -
35
The gamma-ray emission from the Moon seen by Fermi LAT
The Moon is among the brightest gamma-ray sources in the sky, even brighter than the Sun. The lunar regolith serves as target for cosmic-ray nuclei (mainly proton and helium), resulting in the emission of high-energy gamma rays, a process sensitive to both incident cosmic-ray fluxes and the surface composition of the Moon. Using the full 17-year dataset from the Fermi Large Area Telescope (LAT), we measured the Moon gamma-ray spectrum from 30 MeV up to a few GeV and investigated its temporal evolution, observing the expected anticorrelation with solar activity. We developed a dedicated analysis framework in a Moon-centered coordinate system, taking into account that the Moon is a moving target, and applied appropriate rotations to all background components. We also evaluated the gamma-ray yields from cosmic-ray protons and helium nuclei impinging on the lunar surface using FLUKA code. By folding these yields with the time-resolved proton and helium spectra measured by the AMS-02 and PAMELA experiments, we are able to reproduce the temporal evolution of the Moon gamma-ray flux measured by Fermi-LAT.
Speaker: Leonarda Lorusso (Istituto Nazionale di Fisica Nucleare) -
36
Multi-Messenger Emission from Galaxy Clusters: Predictions for Gamma Rays and Neutrinos
Galaxy clusters hosting AGN are promising sources of high-energy gamma rays and neutrinos produced through cosmic-ray (CR) interactions in the intracluster medium (ICM). Motivated by recent Fermi-LAT studies of nearby clusters, including Virgo, Perseus, Coma, and A119, we investigate their non-thermal emission using a numerical framework that combines cosmological magnetohydrodynamic (MHD) simulations with Monte Carlo CR propagation. The MHD simulations provide realistic distributions of gas density, temperature, and magnetic fields, while Monte Carlo simulations model CR transport and the production of secondary gamma rays and neutrinos. Assuming the CR injection follows the gas density of ICM, we calculate the diffuse emission from the Virgo, Perseus, Coma, and A119 clusters.
Our predicted gamma-ray fluxes lie below the current LHAASO upper limits. While the observed MAGIC emission from the central AGN NGC~1275 exceeds the diffuse cluster component, indicating a dominant AGN contribution. We also estimate the cumulative gamma-ray and neutrino emission from nearby galaxy clusters, finding gamma-ray fluxes below the Fermi-LAT diffuse background and neutrino fluxes consistent with current IceCube upper limits. These results provide robust multimessenger constraints on the contribution of galaxy clusters to the diffuse high-energy Universe.Speaker: Dr Saqib Hussain (University of Nova Gorica, Slovenia) -
37
Luminosity function of millisecond pulsars in globular clusters from their gamma-ray spectra
Millisecond pulsars (MSPs) are widely believed to be responsible for the gamma-ray emission of globular clusters (GCs), yet the underlying MSP gamma-ray luminosity function remains uncertain. Existing GC-based determinations of the latter often rely on external prescriptions for the number of MSPs in each cluster.
In this work, we constrain the MSP gamma-ray luminosity function in Milky-Way GCs directly from gamma-ray spectral energy distributions (SEDs), establishing an inference strategy that remains computationally viable for joint analyses of large GC samples.
We construct a forward model in which each GC hosts a population of MSPs whose luminosities are drawn from a universal log-normal luminosity function. Synthetic GC SEDs are generated by summing individual MSP spectra, and we infer posterior distributions using first a likelihood-based nested sampling and then a Bayesian implicit-likelihood inference in the neural ratio estimation (NRE) approach.We show how the likelihood-based nested sampling approach becomes rapidly impractical as the number of jointly modelled clusters (and cluster-specific latent parameters) increases, whereas the NRE approach scales mildly with sample size and reproduces the likelihood-based posteriors in regimes where direct sampling is feasible.
We then apply the implicit-likelihood pipeline to Fermi-LAT SEDs from the 4FGL-DR4 catalog for a sample of 36 GC-associated sources, augmented by dedicated phase-resolved ON/OFF SEDs for two clusters hosting individually detected MSPs.
For the real data sample, we obtain informative constraints on the luminosity-function parameters consistent with previous analyses that constrain the cluster-specific MSP counts via complementary multi-wavelength information.
Speaker: Francesco Xotta (University of Nova Gorica) -
38
Probing High-Energy Particle Dynamics in Spherically Symmetric Environments with SAETASS
The propagation and interaction of cosmic rays in highly energetic astrophysical environments, such as supernova remnants and stellar wind bubbles, are central to modern astroparticle physics. Understanding the intricate interplay between particle diffusion, advection, and energy losses requires solving the cosmic ray transport equation under realistic, yet computationally tractable, conditions.
In this talk, we investigate the complex dynamics of high-energy particles using
SAETASS(Solver for Astroparticle Equation of Transport Analysis in Spherical Symmetry).SAETASSis a newly developed, open-source numerical framework designed to solve the transport equation by accommodating arbitrary dependencies of transport coefficients on space, momentum, and time. This flexibility allows us to go beyond simplified analytical approximations and robustly track the evolution of particle spectra and spatial distributions inside expanding bubble-like sources.We will present recent results on how specific transport mechanisms dictate the non-thermal particle populations in these systems. Furthermore, we will explain how
SAETASScan be used to compare theoretical predictions with gamma-ray observations of stellar cluster wind bubbles and SNRs. This way, we will highlight how numerical modeling of particle transport in this environments is a powerful tool for decoding the underlying astroparticle physics of these accelerators.Speaker: José María García-Morillo (Instituto de Astrofísica de Andalucía (IAA-CSIC))
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34
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Searches for Galactic sources: 2 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Conveners: Sabrina Casanova (Ruhr Universitaet Bochum), Silvia Celli (Istituto Nazionale di Fisica Nucleare)-
39
Prospects on detection of the Fermi Bubbles with CTAO
In 2010, the Fermi Gamma-ray Space Telescope observed two gamma-ray emitting structures, the Fermi Bubbles (FBs), that extend up to 55° above and below the Galactic plane and that seem to emanate from the Galactic center region. Although the spectrum at latitudes |b| > 10° has a softening or a cutoff around 100 GeV, the one at the base of the FBs, |b| <10°, extends up to about 1 TeV without a significant cutoff in the Fermi LAT data. The mechanism behind the FBs production is currently under debate. More observations of the FBs at different energies are required to improve our understanding of their origin.
Recently, H.E.S.S. and HAWC Observatory have set upper limits on the FBs flux. In this work, we assess the sensitivity of the Cherenkov Telescope Array Observatory (CTAO) Alpha Configuration to detect the FBs and investigate the optimal strategies for their detection. We explore detection prospects for low and high-latitude FBs, paying special attention to the transition region. We simulate the observations using Gammapy, the official CTAO high-level science analysis software, considering different spectra for low/high latitude FBs, as well as various benchmark models for their morphologies. We also assess the impact of the Galactic interstellar emission by introducing different state-of-the-art models accounting for the uncertainty in the transport properties in the Galaxy. Finally, we investigate different observational strategies combining the CTAO Galactic Centre Survey and several layouts for the Extended Survey, to maximize the sensitivity to the high-latitude FBs. This study provides a clear observation strategy for the CTAO, based on maximizing the sensitivity for the FBs, which is expected to yield, for the first time, a clear detection of the FBs in this energy range.
Speaker: Nina Bavdaž (University of Nova Gorica) -
40
A multi-wavelength view of Galactic PeVatrons: why MeV matters
The recent discovery of a growing population of Galactic PeVatron candidates by the LHAASO experiment has opened a new era in the study of the origin of Galactic cosmic rays. Despite the detection of gamma rays extending well beyond 100 TeV, the nature of these accelerators remains largely unconstrained. Ultra-high-energy gamma rays alone cannot uniquely establish a hadronic origin, while the limited angular resolution of current TeV-PeV instruments often prevents the unambiguous identification of the emitting source.
In this context, observations in the MeV energy range provide a unique diagnostic of hadronic particle acceleration through the characteristic $\pi^0$-decay feature, the so-called pion bump. While AGILE and Fermi-LAT have demonstrated the power of this signature in a handful of supernova remnants, extending these studies to the newly discovered Galactic PeVatron population represents a crucial step toward identifying the sources responsible for the acceleration of Galactic cosmic rays.
However, MeV observations alone cannot solve the cosmic-ray puzzle. Identifying Galactic PeVatrons requires a comprehensive multi-wavelength and multi-messenger approach, combining radio observations, molecular and ionized gas tracers, X-ray measurements, MeV-GeV and TeV-PeV gamma rays, together with neutrino observations. The synergy among these complementary probes provides the key to disentangling the underlying emission mechanisms and to building a self-consistent picture of particle acceleration, propagation, and interaction in Galactic environments.
In this contribution, we discuss the scientific role of MeV observations within this broader observational framework and highlight how their combination with current and future multi-wavelength and multi-messenger facilities can provide decisive diagnostics for unveiling the origin of Galactic cosmic rays
Speaker: Dr MARTINA CARDILLO (IAPS-INAF) -
41
Surprising Solar-Cycle Evolution of Quiet-Sun Gamma-Ray Emission Observed with Fermi-LAT
The steady-state gamma-ray emission from the quiet Sun originates from interactions of Galactic cosmic rays with the solar atmosphere. This emission consists of two distinct components: a hadronic disk emission produced by pion decay of galactic cosmic rays in the solar atmosphere and a spatially extended inverse-Compton (IC) component generated by cosmic-ray electrons scattering solar photons throughout the inner heliosphere.
Using 15 years of observations with the Fermi Large Area Telescope (Fermi-LAT), we investigate, for the first time, the temporal evolution of these two components separately over Solar Cycle 24 and the beginning of Cycle 25. Their variability is compared with the sunspot number and with Galactic cosmic-ray proton and electron fluxes measured by AMS-02.
The disk emission exhibits the expected behavior, showing a clear anti-correlation with solar activity and a strong correlation with the Galactic cosmic-ray proton flux, confirming its hadronic origin. In contrast, although the extended IC component initially follows the expected solar-cycle modulation, this behavior disappears after the onset of the solar magnetic polarity reversal, with no significant correlation with either sunspot number or cosmic-ray electrons over the full 15-year period.
These findings indicate that cosmic-ray transport and modulation in the inner heliosphere are more complex than predicted by current models and may point to additional physical processes contributing to the observed gamma-ray emission. The quiet Sun therefore provides a unique laboratory for probing cosmic-ray propagation, solar modulation, and particle transport in the inner heliosphere.Speaker: Silvia Raino' (Istituto Nazionale di Fisica Nucleare)
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39
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Indirect Dark Matter detection: 2 Aula C
Aula C
Chemistry Department, University Sapienza
Conveners: Emmanuel Moulin (CEA Saclay), Federica Giacchino (Istituto Nazionale di Fisica Nucleare)-
42
Dark Matter search towards dwarf galaxies with H.E.S.S
Four dwarf galaxies Sculptor, Fornax, Leo II, and Segue II were observed with the High Energy Stereoscopic System (H.E.S.S.) between 2004 and 2023, corresponding to a total exposure of 81.2 hours. No statistically significant gamma-ray excess was detected from any of these targets. To assess the impact of systematics related to the dark matter distribution, several spatial models, including both spherical and non-spherical morphologies, were investigated. A common spectral framework was adopted for a range of dark matter annihilation channels. Upper limits were derived on the velocity-averaged annihilation cross section, with the most stringent constraints reaching the level of ⟨σv⟩ ≈ 10⁻²³ cm³ s⁻¹ over the explored dark matter mass range. In parallel, dark matter decay scenarios were also considered, allowing lower limits to be placed on the dark matter particle lifetime. These results provide new constraints on particle dark matter properties.
Speaker: Titouan Girault (IRFU, CEA Paris-Saclay, Université Paris-Saclay) -
43
Search for Long Lived Particles with the IceCube Neutrino Observatory
We present the first-ever search for Long-Lived Particles (LLPs) produced by atmospheric muons with the IceCube neutrino telescope, a state-of-the-art neutrino detector located 2 km below the South Pole ice. IceCube’s kilometer-scale size, optimized for astrophysical neutrino detection, also provides a unique opportunity for rare particle physics searches.
Atmospheric muons, disregarded as background in most IceCube analyses, reach the detector at a kilohertz rate. These muons could produce LLPs in the detector volume via an exotic muon–nucleus bremsstrahlung-like scattering, which would travel undetected for some distance before decaying back into Standard Model particles, creating a distinct “dark gap" - a segment without Cherenkov light in the otherwise bright muon track. Identifying these rare signatures within the sparse detector geometry is a significant challenge, but provides a probe into new physics scenarios involving feebly interacting particles with long lifetimes.
This analysis could complement collider-based searches for LLPs by probing long decay lengths in a large, naturally thick detector medium, potentially offering a novel window into feebly interacting new physics.Speaker: Axel Pontén (Uppsala University) -
44
Weighing the Dark Matter mass with Extreme Mass-Ratio Inspirals in LISA
Extreme mass-ratio inspirals (EMRIs) observed by LISA will provide exquisitely precise probes of supermassive black hole environments. In this talk, I will examine the imprint of a dark matter particle’s mass on EMRI waveforms. First, I will show how light, axion-like or scalar dark matter particles modify the gravitational dynamics between two black holes in an EMRI system, and how relativistic waveform modelling can be used to assess detectability of the precise mass of the dark matter particles. I will then identify the regions of the dark matter particle’s mass that can be tested with future space-based gravitational-wave observations. These results point to a new route for constraining the particle nature of dark matter complementary to conventional searches.
Speaker: Theo Karydas (GRAPPA, University of Amsterdam) -
45
Probing Dark Matter in the Galactic Center with CTAO: Sensitivity and Morphology Insights
The Galactic Center (GC) is one of the preferred targets in the search for gamma-ray signals of thermal dark matter (DM) due to its proximity and high DM content. Despite being rich in very diverse gamma-ray astrophysical emissions, even in the absence of clear signals, GC observations yield the strongest constraints for well-known DM models, such as WIMPs. In this context, the forthcoming Cherenkov Telescope Array Observatory (CTAO) will improve current sensitivity studies in the TeV regime, thanks to its expected angular resolution and flux sensitivity. In this work, we focus on a wide range of cuspy and spiked DM density profiles, including recent models of the GC astrophysical emission. We estimate the expected sensitivity of the CTAO to a DM annihilation signal within the inner 3.5º of the GC. Starting from the previous CTAO Consortium study [A. Acharyya et al JCAP01(2021)057], we first update the detection prospects and projected upper limits on the annihilation cross-section for those profiles, showing that the projected constraints are expected to rule out the thermal relic cross-section from ∼100 GeV to ∼40 TeV for NFW or Einasto profiles, or even more for spiked profiles. Secondly, we present a novel approach to recover information on the DM density profile without assuming any specific morphology or spatial templates. This approach allows us to recover valuable information on the morphology of the DM density distribution in the inner ∼500 pc of the GC, where the dynamical constraints alone cannot give robust constraints. We find that, in the conservative case of absence of a DM signal, the gNFW profiles can be ruled out for γ≳1 at the 95% confidence level, depending on the DM mass.
Speaker: Jaume Zuriaga-Puig (IFT UAM-CSIC)
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42
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Poster session: poster esposition and presentation
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46
The impact of wind-blown bubbles on pulsar wind nebulae and supernova remnants
Pulsar wind nebulae (PWNe) seem to be the most common gamma-ray sources in recent surveys of the very-high-energy and ultra-high-energy sky (with HESS, HAWC, or LHAASO). They are formed by the interaction of a relativistic pulsar wind with the stellar ejecta of the parent supernova remnant (SNR). Electron-positron pairs accelerated in the vicinity of the pulsar and diffusing away across the shocked pulsar wind nebula produce spatially and spectrally extended emission through the synchrotron and inverse-Compton scattering radiation processes.
Over the past decades, developments in gamma-ray observations and data analysis techniques have revealed very extended sources and/or multiple emission component in gamma-ray sources coincident with powerful pulsars. This is hard to reconcile with simple model predictions for PWNe, which are commonly performed under the assumption that the parent SNR expands in a uniform interstellar medium (ISM). Moreover, in many cases, the parent SNR is not detected, casting further doubt on such a description of the SNR evolution. Yet, pulsars are born from massive stars, whose powerful winds excavate large cavities around them. Supernovae explode in such stratified wind-blown bubbles (WBBs) that drastically differ from the uniform average ISM.
We investigated how this environment affects the development of an SNR-PWN system. We performed a series of numerical experiments in which we implemented a 1D hydrodynamical analog of a SNR-PWN system and followed its evolution inside a WBB. This revealed many fundamental differences in the SNR and PWN evolutions, in terms of spatial extent, dynamics, energy content, and thermal X-ray signature. In advanced stages, those expected to characterise many gamma-ray PWNe, both the SNR and the PWN are larger by factors of a few, and the former emits very little thermal X-rays while the latter holds much more energy. Our findings therefore provide a convenient explanation for the above-mentioned observational puzzles.
Speaker: Lioni-Moana Bourguinat (Gran Sasso Science Institute (GSSI, Italy)) -
47
An optical-mid-infrared color evolution tool for nova identification using WISE data.
Novae are key tracers of accretion processes and contribute to the chemical and dynamical evolution of the Galaxy. However, optical surveys miss a significant fraction of nova eruptions due to interstellar extinction, particularly toward the Galactic plane. We present two contributions. First, we developed an infrared-based pipeline to identify nova candidates from WISE data using infrared variability criteria, validated against 62 optically confirmed novae, and identify 54 additional candidates lacking optical classification. This infrared-selected sample suggests that extinction causes optical surveys to miss a significant fraction of Galactic nova eruptions, with the WISE color distribution indicating a possible incompleteness of $\sim$30\%. Second, we introduce the extinction-corrected $(V-W1)_0$ color evolution as a photometric diagnostic of nova ejecta expansion and cooling timescale, enabling nova type classification and follow-up prioritization from infrared data alone. We found a strong correlation between the $(V-W1)_0$ peak color and the optical-to-$W1$ peak time delay (Pearson $r = 0.90$, $p < 0.01$), consistent with the delay tracing the duration of the mass-loss phase, and a further correlation between peak color and the rate of color decline over the first 60 days after the $(V-W1)_0$ peak. Together these diagnostics can classify nova type from purely photometric infrared data and separate novae from contaminants. Infrared time-domain surveys provide a powerful complementary tool to optical searches and are essential for obtaining a more complete census of Galactic novae and improving estimates of the Galactic nova rate.
Speaker: Joseph Onuegbu (Ariel University, Israel) -
48
Axion-Like Electrophilic Portal for Pion Dark Matter
We investigate a scenario where Strongly Interacting Massive Particle (SIMP) dark matter interacts with an axion-like particle (ALP) that couples exclusively to electrons. This minimal setup provides interactions which enforce thermal equilibrium between dark matter and the SM in the early Universe. We analyze the cosmological evolution of the dark sector and the constraints arising from dark matter annihilations, ALP laboratory searches and astrophysical observations. Our results show that the allowed parameter space is wider than previous studies and
an ALP with mass $m_a \sim {\cal O}(10)~\text{MeV}$ can act as a viable portal between the visible and dark sectors. Interestingly, this mass range overlaps with the parameter space suggested by the reported $X_{17}$ anomaly.
Furthermore, the introduction of non-vanishing $\theta$ angle in the dark sector of the model opens up the parameter space to heavy ALP masses.Speaker: Federico Mescia (Istituto Nazionale di Fisica Nucleare) -
49
How invisible can axions be?
We investigate the scenario of maximally invisible axions, i.e. QCD axions interacting with matter only through the irreducible couplings generated by the operator $\frac{a}{f_a} \frac{g_s^2}{32 \pi^2} G_{\mu \nu}^a \tilde{G}^{a, \mu \nu}$. In particular, we first analyse maximally invisible axion production in supernovae, by determining the relevant SN1987A bound and by presenting the emission spectra for the dominant production channels, namely nucleon-nucleon bremsstrahlung and pion conversion. We then explore the possibility of detection of maximally invisible axions in Cherenkov detectors, with the aim to define a lower limit on overall QCD axion detectability.
Speaker: Alessandro Lella (Istituto Nazionale di Fisica Nucleare) -
50
Optimizing Divergent Pointing configurations for CTAO to study poorly localised GRBs
Gamma-ray bursts (GRBs) are among the most energetic and enigmatic transient phenomena in the Universe, originating either from the collapse of massive stars or from the merger of compact-object systems, such as neutron star–neutron star binaries. These short-lived, extragalactic, and unpredictable events pose significant challenges for observations at very-high energies (VHE; i.e., E > 20 GeV), particularly due to their rarity and often poor initial localization.
The Cherenkov Telescope Array Observatory (CTAO) represents the next generation of Imaging Atmospheric Cherenkov Telescopes and is designed to be the most sensitive ground-based observatory for VHE gamma-ray astronomy. With its unprecedented sensitivity and wide energy coverage from approximately 20 GeV to 300 TeV, CTAO will provide a unique opportunity to increase the number of GRBs detected at VHE and to probe their underlying physics. While the standard CTAO pointing mode is optimized for targeted observations, alternative strategies such as divergent pointing—where individual telescopes are offset to cover a wider sky region—can significantly expand the instantaneous field of view. This approach is particularly well-suited for GRB follow-up observations, where rapid coverage of large and poorly localized regions is essential.
In this contribution, we present simulation-based studies of divergent pointing configurations optimized for poorly localized GRBs and for follow-ups of multi-messenger events, such as the gravitational-wave counterpart of binary neutron-star mergers, and we assess the impact of this strategy on CTAO array performance and GRB detection prospects.
Speaker: Jahanvi Jahanvi (University of Udine and INFN-Trieste) -
51
A Multi-Wavelength Study of Gamma-Ray Burst 240825A
Gamma-Ray Bursts (GRBs) are the brightest known explosions in the Universe and provide a unique opportunity for studying particle acceleration and radiation processes under extreme conditions. The recent detections of Very High Energy (VHE, >100 GeV) emission from a small number of GRBs have provided new insights into their underlying physics. In particular, VHE observations provide valuable constraints on the origin of the emission, including the possible contribution of synchrotron self-Compton (SSC) processes. In this thesis, the multi-wavelength properties of GRB 240825A, a bright, unusually short type II GRB located at a redshift of z = 0.659, are investigated.
Swift-XRT and ALMA observations were analysed and combined with publicly available optical data to construct a multi-wavelength light curve and spectral energy distribution. The temporal evolution is consistent with the typical prompt and afterglow phases of GRBs, while spectral modelling suggests that SSC processes could produce emission extending into the VHE regime. Although significant parameter degeneracies remain, the modelling favours a dust-obscured environment for GRB 240825A, with circumburst properties broadly consistent with a Wolf-Rayet progenitor scenario. VHE observations with current and next-generation facilities such as H.E.S.S. and CTAO, combined with extended simultaneous multi-wavelength observations, will be crucial for constraining the VHE emission mechanisms and the underlying physical parameters.
Speaker: Dirk van der Geest (Kapteyn, RUG) -
52
Swift gives a new BAT-GLIMPSE: Gamma-ray Localization using Imaging and Mosaic techniques for Pointing and Slew Epochs
The Burst Alert Telescope (BAT) onboard the Neil Gehrels Swift Observatory represents a cornerstone of high-energy astrophysics, thanks to its success in the systematic detection and precise localization of transient gamma-ray sources. However, the onboard triggering system is disabled during spacecraft slews, a growing blind spot as Swift spends more time executing Target of Opportunity observations. We present BAT-GLIMPSE, a fully autonomous, open-source pipeline that combines coded-mask imaging and mosaicking to recover arcminute-precision localizations of gamma-ray transients in both pointed and slewing modes. Validated on 66 GRBs from the GCN archive, the pipeline recovers 43 events with ≲5 arcmin accuracy, including 88% of those occurring during slews. Operating alongside the NITRATES pipeline, BAT-GLIMPSE has become a critical component of the extreme low-latency response of Swift to early-warning pre-merger gravitational-wave alerts, under the ULTRA-Swift program. Together, the two pipelines are estimated to double BAT onboard arcminute-localization rate, a substantial sensitivity gain that unlocks the full discovery potential of Swift for GRBs, gravitational-wave counterparts, and other multi-messenger transients. The approach is directly transferable to other current and future coded-mask missions, extending its impact beyond the Swift era.
Speaker: Samuele Ronchini (Istituto Nazionale di Fisica Nucleare) -
53
Resonant Axion-Photon Conversion in the Early Inspiral of Neutron Star Binaries
We consider the early binary neutron star inspiral phase as a scenario to probe environmental axion–photon resonant conversion. For this we approximately model the merger site electromagnetic fields as the superposition of two rotating dipolar stellar magnetic fields at the thousand–km scale when both magnetospheres are not largely distorted. We capture the time-sliced near-zone magnetospheric geometry relevant for axion–photon mixing. Plasma effects are incorporated through an effective Goldreich–Julian charge density, used to determine the effective plasma frequency and the location of resonant conversion surfaces. Our results show that axion–photon resonant conversion in binary magnetospheres mostly occurs on extended peanut-shaped surfaces whose global geometry evolves as the binary inspiral evolves. As a consequence, the total electromagnetic power emitted through axion–photon conversion exhibits a characteristic dependence on axion mass and a slow temporal modulation correlated with the gravitational wave frequency emission. This feature is potentially detectable for ma ∈ [50, 170] μeV and set $g_{aγ} ≲ 10^{−11} \rm GeV^{−1}$ as it lies within the sensitivity limits of current or planned radio observation missions. In light of our results we discuss the opportunity of binary neutron star inspirals as time-dependent, multimessenger probes of axion physics, and motivate coordinated searches combining gravitational wave observations with radio and millimeter wavelength electromagnetic measurements.
Speaker: Duvier Suarez-Fontanella (Universidad de Salamanca) -
54
Multi-Messenger Modelling of Hadronic Emission from Massive Star Clusters in the Cygnus Bubble
We investigate particle acceleration at termination shocks of massive star clusters in the Cygnus region, one of the most promising Galactic PeVatron candidates. Within the framework of a cluster-wind acceleration model, we fit the latest spatially and spectrally resolved measurements of ultra-high-energy $\gamma$-ray emission from the Cygnus bubble to constrain the physical conditions of the accelerator. A joint analysis of the $\gamma$-ray spectrum and morphology yields constraints on the maximum particle energy, acceleration efficiency, magnetic-field strength, shock geometry, and on the plausibility of a predominantly hadronic origin of the emission. We further incorporate an updated gas-density distribution constructed from new molecular-line observations obtained with the Purple Mountain Observatory (Delingha), thereby refining predictions for hadronic $\gamma$-ray and neutrino production. Using these improved environmental constraints, we calculate the expected high-energy neutrino flux from the Cygnus bubble and assess its detectability with current and forthcoming generations of neutrino observatories.
Speaker: Abhijit Roy (GSSI - Istituto Nazionale di Fisica Nucleare) -
55
A multi-modal approach for the classification of multimessenger events involving gravitational waves and IACT data
The first multimessenger observation involving gravitational waves, GW170817, demonstrated the essential role of combining information from different messengers and from the entire electromagnetic spectrum to achieve a comprehensive understanding of astrophysical phenomena. In the coming years, the Cherenkov Telescope Array Observatory (CTAO) — the largest and most sensitive ground-based very-high-energy gamma-ray facility — will begin operations, and is expected to observe a substantial number of events jointly with the gravitational-wave detector network. This motivates the development of fast and robust analysis strategies capable of promptly extracting data features, including the ability to distinguish genuine multimessenger events from coincidental detections.
In this work, I present a first implementation of a multimodal machine-learning (MMML) approach that combines IACT data and gravitational-wave data to classify candidate multimessenger events.Speaker: Dr Claudio Gasbarra (INFN Roma Tor Vergata) -
56
Classification of blazar flares and their characteristic emission signatures
Blazars are one of the most extreme objects in the universe: powerful AGNs with their jets pointing towards Earth. However, their electromagnetic multiwavelength emission is not yet fully understood. While the lower energy emission is believed to be produced by relativistic leptons, the origin of the gamma-rays detected from these sources is still uncertain. In many cases, a variety of different models can fit the data equally well. Additionally, blazars are often highly variable objects.
In this work we are investigating how the behaviour of blazar flares could help to distinguish different leptonic and lepto-hadronic emission scenarios. Assuming that all of the nonthermal emission originates from the blazar jet, we consider different physical flare origins, such as flares caused by enhancements of external radiation fields, clouds traversing the jet, changes in particle injection and magnetic fields, single zones dominating the emission, and also continuous jet models. Then we explore their observational signatures in different wavelength bands and their potential neutrino emission, compare them to each other, and investigate which characteristic features could be used to discern different scenarios and emission mechanisms. While the identification of the underlying physical scenario is often not unique and different physical mechanisms can lead to similar flare behaviour, important information can be extracted in certain cases.Speaker: Mischa Breuhaus
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46
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Plenary: 6 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Chair Aldo Morselli
Convener: Dr Silvia Celli (Istituto Nazionale di Fisica Nucleare)-
57
Multiwavelength and Multimessenger properties of PeVatrons
This talk highlights the fundamental acceleration and radiation mechanisms operating in electron and proton PeVatrons. I will outline the multiwavelength properties of Galactic PeVatrons and discuss strategies for discovering and exploring these sources using ultra-high-energy gamma rays and neutrinos.
Speaker: Felix Aharonian (Dublin Institute for Advanced Studies) -
58
LHAASO Discovers Black Hole Driven PeVatrons (μ-Quasars) and Precisely Measures the PeV-Component in the Proton/Helium Spectra
LHAASO discovers “high energy” component in the CR proton and helium spectra at the “knee”, indicates new population of CR sources. It is clearly different from the “low energy” component which is traditionally regarded as originated from supernova remnants. LHAASO has provided strong evidences of the HECRs from SNRs, however limited Emax < Eknee~3.6 PeV. The new HE population most likely consists of black holes, more specifically μ-Quasars. The extreme case is Cgy X-3, the historical super-star that ignited the whole TeV γ-astronomy. Now LHAASO found it a super-PeVatron. In a range of ~10° surrounding it, the huge LHAASO Bubble has still very mystery origin. Future experiments are highly anticipated with higher spatial resolution in the UHE γ-ray band for investigation in depth and ultimately identification of their companion neutrino emissions.
Speaker: Zhen Cao (Institute of High Energy Physics) -
59
Particle acceleration at the head of micro-quasar's jets
Recent results from gamma-ray observatories show an intriguing association between Galactic micro-quasars and high-energy gamma-ray sources that, is some cases, reach PeV energies. These findings suggest that micro-quasars may represent the long-sought PeVatrons that are responsible for cosmic ray acceleration up to the energies of PeV and possibly beyond. However, the physical mechanism responsible for particle acceleration in micro-quasars is still debated. In this talk I will discuss possible acceleration sites connected with the micro-quasars jets. In particular I will show how internal shocks and the termination shocks formed at the head of the jet can both be efficient sites where PeV energies may be achieved. Finally, I will compare the predicted gamma-ray emission for hadronic scenario with some of the micro-quasars detected by LHAASO.
Speaker: Giovanni Morlino (INAF/Oss. Astrofisico di Arcetri)
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57
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10:30 AM
Group photo and Coffe break
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Plenary: 7 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Chair Aldo Morselli
Convener: Prof. Amy Connolly-
60
Latest Results and News from the IceCube Neutrino Observatory
The IceCube Neutrino Observatory, built into a cubic kilometer of ice at the South Pole, was completed in 2010 and has been in continuous operation since then. Following the discovery of high-energy astrophysical neutrinos in 2013, there has been steady progress in measuring the diffuse extragalactic flux and identifying a few of the individually faint sources that contribute to it. Recently the neutrino flux from our own Milky Way has been detected as well, inaugurating the field of Galactic neutrino astronomy. In this talk I will discuss some of the latest results in these areas and also report on the installation of the IceCube Upgrade this past winter, which adds significant new capabilities to IceCube and represents an important milestone towards the next generation IceCube-Gen2.
Speaker: Finley Chad (Stockholm University) -
61
Neutrinos from the Cosmos: Latest Results from KM3NeT
KM3NeT is a deep-sea neutrino telescope located in the Mediterranean Sea, consisting of two detectors: ORCA, offshore from Toulon, France, and ARCA, offshore from Sicily, Italy. Their designs are optimized for the detection of neutrinos in two complementary energy ranges, from the GeV range with ORCA to the TeV–PeV range with ARCA. Both detectors are currently under construction, with approximately half and one quarter of their final volumes deployed, respectively.
ARCA is the KM3NeT detector primarily designed for neutrino astronomy, combining a large instrumented volume with exceptional angular resolution. Already in its partial-detector configuration, ARCA achieved the landmark detection of an ultra-high-energy neutrino, marking a major milestone in high-energy neutrino astronomy. ORCA, although designed for neutrino oscillation studies using atmospheric neutrinos, complements the astrophysical programme of the experiment by extending its sensitivity to lower energies.
The latest results from searches for astrophysical neutrinos using data collected with the KM3NeT detectors are presented in this contribution.Speaker: Giulia Illuminati (INFN Bologna) -
62
Measurements of Neutrino Oscillations with KM3NeT
KM3NeT/ORCA is a new generation neutrino telescope under construction in the Mediterranean Sea off-shore Toulon. With an instrumented water mass of about 6 Mtons and an energy threshold as low as 2 GeV it will harvest almost 100,000 neutrino events per year. This wealth of data will allow to perform competitive precision measurements in the GeV energy range. The determination of the hitherto unknown neutrino mass ordering can be addressed as well as a precision measurement of the neutrino oscillation parameters dm2_31 and th_23. Further, KM3NeT/ORCA will accumulate one of the world largest samples of tau neutrino interactions and will make important contribution to neutrino astronomy in the neutrino energy range below 10 TeV. Progress of the detector construction and first results from early data will be presented and the physics potential of KM3NeT/ORCA at the end of the decade will be discussed.
Speaker: Juergen Brunner (CPPM)
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60
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1:00 PM
Lunch Break
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Hardware and Software developments for HE astroparticle physics: 1 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
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63
Directional reconstruction of IceCube neutrinos using transformer-encoded normalizing flows
The directional reconstruction of IceCube neutrinos, including the estimation of uncertainties, is essential for point source searches. In this talk we summarize recent work on the estimation of the per-event directional posterior using machine learning, in particular transformers and normalizing flows. The new method yields new state-of-the-art angular resolutions for the two major event topologies: neutrino-induced showers and neutrino-induced muon tracks.
Speaker: Thorsten Glüsenkamp (Stockholm University) -
64
Artificial Intelligence Methods in Particle Accelerator Physics
Particle accelerators have long represented fundamental tools for physics, both in basic research and in technological and industrial applications, while also constituting an important intersection between particle physics, cosmology, and modern astrophysics.
The intrinsic complexity of these systems, characterized by a large number of operational parameters and costly diagnostic procedures, requires accurate, fast, and reliable control strategies. In this context, machine learning techniques represent advanced tools for automation, diagnostics, and operational optimization.
Virtual diagnostic systems can be developed using neural networks and dimensionality reduction techniques enabling the realization of digital twins for accelerator facilities. Reinforcement learning algorithms, such as Soft Actor-Critic (SAC), can be integrated into event-driven architectures to dynamically optimize complex procedures, including RF conditioning of accelerating structures. Additional developments include the integration of Large Language Models (LLMs) for operator–machine interaction and the use of convolutional neural networks for forecasting interlock events from time-series data.
The proposed methodologies are highly versatile and applicable not only to particle accelerators, but more broadly to several areas of applied physics, contributing to more standardized, reproducible, and optimized operational procedures.Speaker: Giulia Latini (Istituto Nazionale di Fisica Nucleare) -
65
Description and characterization of a stereoscopic trigger system between the CTAO LST-1 and the MAGIC telescopes
We present the implementation and validation of a hardware stereoscopic trigger (HaST) connecting the Large-Sized Telescope prototype (LST-1) of the Cherenkov Telescope Array Observatory (CTAO) with the Major Atmospheric Gamma-ray Imaging Cherenkov Telescope (MAGIC) at the Roque de los Muchachos Observatory. This setup enables real-time exchange of camera-level trigger signals, enabling joint data acquisition and providing a commissioning platform for the future 4-LST HaST system.
The performance of the system was characterized through trigger rate scans, coincidence window optimization, and timing distribution analyses.
The results demonstrate the technical feasability of the LST-1 HaST and confirm its role as both a proof of concept and a realistic test bench for the trigger architecture to be deployed in future CTAO operations.
Speaker: Alejandro Pérez Aguilera (UCM - IPARCOS) -
66
AI for astroparticles: Generative Artificial Intelligence for Air Shower Simulation
Simulating extensive air showers is a major computational effort for the study of astroparticles in general. As the interest of the scientific community is moving towards ultra-high energies and rare events, it is becoming increasingly important to generate high statistics well beyond the PeV scale. The conventional approach to use "ab initio" simulations is extremely demanding in terms of wall time, energy cost and hardware. The GAIAS2 project successfully demonstrated a novel approach, using Generative Adversarial Networks (GANs) to dramatically reduce the simulation time and the energy consumption. As an example of application, a training dataset of high-energy primary protons has been simulated using CORSIKA and we quantitatively show that the GANs can correctly reproduce the spatial distribution of muons at ground level and their energy spectrum. The level of agreement is sufficient for downstream analyses such as direction reconstruction and energy estimation. As the real time per shower is reduced by a factor 10000 for showers beyond a few PeV, machine-learning-based generators qualify as a cheap and effective booster for astroparticle and multimessenger astronomy research.
Speaker: Cristiano Bozza (Istituto Nazionale di Fisica Nucleare) -
67
Exploring Divergent Pointing mode with CTAO: Performance and Science Prospects
The Cherenkov Telescope Array Observatory (CTAO) represents the next generation of Imaging Atmospheric Cherenkov Telescopes and is designed to be the most sensitive ground-based observatory for very-high-energy (VHE; E > 20 GeV) gamma-ray astronomy. With two arrays located in the Northern and Southern hemispheres, CTAO will provide full-sky coverage with unprecedented sensitivity over a broad energy range, from about 20 GeV up to 300 TeV.
The standard observation mode for IACTs is the parallel pointing configuration, in which all telescopes are aligned toward the same sky region. This approach
maximizes event reconstruction quality, enabling high angular resolution with an accurate background rejection. Thanks to the large number of telescopes
deployed at both sites, CTAO will enable the exploration of complementary pointing strategies. Among these, the divergent pointing mode consists of
individual telescopes directed slightly offset from a common central direction, effectively increasing the instantaneous field of view. This configuration is
well-suited for wide-area surveys and the follow-up of poorly localized transient events, including gravitational-wave events, gamma-ray bursts, and
high-energy neutrino alerts. This gain in field of view, however, comes at the cost of a reduced on-axis performance, with a degradation in sensitivity, angular
resolution, and background rejection compared to the standard parallel configuration.In this work, we present a performance study of the divergent pointing mode based on dedicated Monte Carlo simulations for both CTAO arrays using Hillas-based event reconstruction. We assess performance with the increased field of view, including sensitivity, angular and energy resolution, and discuss its potential role in future CTAO observing strategies. Our preliminary results indicate that the off-axis sensitivity of the divergent pointing configuration can surpass that of the parallel configuration, and its effective area is enhanced at low energies for large offset angles, while the on-axis performance remains better in the parallel pointing mode, thereby reinforcing the suitability of this approach for wide-field and transient-driven observations.
Speaker: Jahanvi Jahanvi (University of Udine and INFN-Trieste) -
68
Progress Towards the Production SST Camera of the Cherenkov Telescope Array Observatory
The Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based TeV gamma-ray observatory which will observe the entire sky with improved sensitivity and angular resolution compared to the current generation of imaging atmospheric Cherenkov telescope (IACT) observatories. CTAO will comprise three telescope sizes: Small, Medium, and Large, to cover an energy range of 20 GeV to 300 TeV.
The Small-Sized Telescope (SST) will be the most numerous telescope type in CTAO, with 37 installed at the CTAO-South site in its Alpha configuration. Featuring a dual-mirror Schwarzschild-Couder optical design and a camera comprising 2048 silicon photomultiplier pixels, the SST is designed to observe the highest-energy gamma rays. The SST Camera is nearing its final design with the first production camera to be installed at the CTAO-South site in early 2027.
This contribution presents the latest status of the SST Camera development, including laboratory characterisation and on-telescope investigations of the SST pre-production prototype Cherenkov imaging camera.
Speaker: Connor Duffy (Kapteyn Astronomical Institute, University of Groningen)
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63
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High Energy Cosmic Rays Aula A
Aula A
Chemistry Department, University Sapienza
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69
Measurement of the Elongation Rate in the Context of Mass Composition of Ultra-High-Energy Cosmic Rays at the Pierre Auger Observatory
The Pierre Auger Observatory is the largest hybrid detector for measuring extensive air showers (EAS) induced by ultra-high-energy cosmic rays (UHECRs). The two main components of the Observatory are the Surface Detector (SD) and the Fluorescence Detector (FD), which consists of 27 optical telescopes. The FD measures the depth of the EAS maximum, $X_\mathrm{max}$, but due to its sensitivity, it operates only during moonless nights. Direct measurements are therefore statistically limited by a duty cycle of about 15\%. Conversely, the SD, comprising 1660 Water Cherenkov Detector stations, covers an area of $3000\,\text{km}^2$, and operates almost continuously. Recently, machine learning methods have been developed to reconstruct $X_\mathrm{max}$ from SD measurements of the EAS footprint, significantly increasing both the statistics and the energy range of $X_\mathrm{max}$ measurements. Before undergoing a major upgrade in 2021, the Observatory also included the Auger Engineering Radio Array (AERA), which featured 124 radio antennas. AERA was later replaced by the Radio Detector, which now covers the entire area of the SD. In this contribution, we show that the reconstructed energy evolution of $\langle X_\mathrm{max}\rangle$ and $\sigma(X_\mathrm{max})$ from the SD are compatible with the measurements from the FD and AERA at lower energies. We also present the interpretation of the elongation rate in the context of the mass composition of UHECRs.
Speaker: Berenika Čermáková -
70
A Decade of Cosmic-Ray Observations with the CALET Experiment on the International Space Station
The CALorimetric Electron Telescope (CALET), an international astroparticle physics
mission developed by a Japanese-Italian-US collaboration, has been operating
continuously and flawlessly on the International Space Station (ISS) since October
2015. Equipped with a deep, hybrid calorimeter capable of high-precision charge and
energy measurements, CALET is designed to measure the electron and positron
spectrum up to 20 TeV (and gamma rays up to 10 TeV), aiming to identify potential
nearby cosmic sources and signatures of dark matter.
This contribution presents the scientific highlights of CALET spanning over a decade
of continuous data acquisition, during which the instrument has recorded
approximately 20 million events above 10 GeV per month. Key results include the
precise measurement of the cosmic-ray electron + positron spectrum, revealing
significant, unexpected deviations from a conventional power-law behavior around 1
TeV. Similar spectral structures and deviations have also been observed in the spectra
of protons, helium, and heavier cosmic nuclei measured up to the PeV scale.
Furthermore, we report on the relative abundances of ultra-heavy galactic cosmic rays
(UHGCR) from Z = 28 (nickel) through Z = 44 (ruthenium).
Beyond hadronic and leptonic cosmic rays, CALET's multi-messenger capabilities are
highlighted through observations of trans-GeV gamma-rays, X-ray and soft gamma-ray
transients detected by the CALET Gamma-Ray Burst Monitor (CGBM), and searches
for electromagnetic counterparts to LIGO/Virgo gravitational wave events. Finally, we
address CALET’s observations of solar modulation and space weather, highlighting its
versatile contribution to high-energy astrophysics.Speaker: Francesco Stolzi (Istituto Nazionale di Fisica Nucleare) -
71
Latest results in cosmic-ray physics from the IceCube Observatory
The IceCube Observatory combines a cubic-kilometer deep-ice detector array with IceTop, a surface cosmic-ray air-shower detector. IceTop’s altitude of 2835 m a.s.l. and area of 1 km$^2$ enable studies of cosmic rays from PeV to EeV energies, covering the knee and the Galactic-to-extragalactic transition region. With its unique setup, IceCube can perform coincident measurements between the surface and in-ice arrays, providing sensitivity to TeV muons produced in air showers. This contribution will review IceCube's measurements of cosmic-ray flux and mass composition, air-shower muon content to test hadronic interaction models, and anisotropy of the cosmic-ray arrival direction distribution. Recent efforts in reconstruction and analysis, aimed at extending the accessible energies down to 200 TeV and beyond the EeV range, will also be discussed.
Speaker: Andrea Parenti (Université Libre de Bruxelles) -
72
Towards a Universal Photon–Hadron Discriminant for Surface Detector Arrays
Efficient discrimination between photon- and hadron-induced extensive air showers remains a key challenge for ground-based cosmic-ray observatories employing surface detector arrays. The objective of this work is to identify observables that remain effective over a wide range of shower geometries while retaining a clear physical interpretation. Using Monte Carlo simulations of photon- and hadron-induced showers at energies around 10^17.5 eV, reconstructed with a 750 m-spacing surface detector array as a case study, a broad set of candidate variables is derived from the temporal and lateral properties of reconstructed air showers. These variables are evaluated in terms of their photon-hadron separation performance. Their dependence on shower geometry, particularly the zenith angle, is investigated to identify variables that retain discrimination power over a wide angular range, while possible azimuthal dependence is also examined. Individual variables lose separation power substantially in different zenith angle ranges, motivating the combination of several variables that each capture a different shower property. Building on these results, a compact discriminant combining timing and lateral observables is constructed. Within the investigated energy range, this combination recovers angular universality and achieves strong overall discrimination performance. The proposed method offers a transparent framework for constructing robust photon–hadron discriminants from timing and lateral observables and can be extended to any detector configuration and other energy ranges.
Speaker: Nataliia Borodai (Institute of Nuclear Physics PAN, Krakow) -
73
DAMPE: Ten Years in Space
The DArk Matter Particle Explorer (DAMPE) is a satellite-borne, calorimetric-type particle detector operating smoothly in space for over ten years since its launch in December 2015. DAMPE is designed to detect cosmic rays and gamma rays up to unprecedentedly high energies, benefiting from its large geometric factor and thick imaging calorimeter. Its outstanding charge and energy resolution empower DAMPE to address major scientific goals, including the indirect search for dark matter in space, cosmic-ray physics, and gamma-ray astronomy.
Over the years, key evidence of peculiar features in CR spectra have been obtained for the first time with high precision, while other phenomena have been firmly confirmed. Moreover, additional analyses—such as high-energy cross-section measurements, searches for fractionally charged particles, and studies of Forbush decreases—have been successfully carried out.
After a brief review of detector performance, the latest scientific results will be presented and discussed, together with highlights from ongoing analyses.
Speaker: Prof. Francesco De Palma (Università del Salento & INFN) -
74
Results and future perspectives on the measurement of the muon content of air showers with the Pierre Auger Observatory
The Pierre Auger Observatory, the world’s largest observatory of ultra-high-energy cosmic rays (UHECR), offers a unique insight into the properties of hadronic interactions occurring in air showers at energies well above those reached at human-made accelerators. While the properties of the electromagnetic part of the showers are largely universal, the production of muons in the showers is highly sensitive to both the nature of the primary particle and to the properties of hadronic interactions. Here, the Pierre Auger Observatory particularly benefits from its hybrid character, as it can use various combinations of observables from different parts of the Observatory to disentangle those dependencies and thus use the muon content of the shower to shed light on both the primary composition and hadronic interactions. Several different analyses using data from surface, fluorescence and radio detectors of the Observatory show a discrepancy between the predictions of simulations based on the latest hadronic interaction models and data. This discrepancy has long been interpreted solely as a deficit in the number of muons predicted by the simulations with respect to the data, but recent results show that the disagreement between models and data is more complex and involves the predictions for the depths of the maxima of the longitudinal shower development as well. At the same time, measurements of shower-to-shower fluctuations of the muon number using inclined hybrid events show good agreement with the predictions, suggesting that the observed muon discrepancy is rather the result of a gradual accumulation of small changes during the shower development than of a major change in the properties of the first interaction. Recently, the Observatory has undergone a significant upgrade, which includes several components aimed at a significant enhancement of its capabilities to measure of the muon content of the air showers.
Speaker: Jan Ebr (Institue of Physics, Prague)
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69
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H.E. astrophysical Neutrino detection: 1 Aula C
Aula C
Chemistry Department, University Sapienza
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75
Galactic Diffuse high-energy neutrino emission, a multimessenger picture
The KRA gamma model — based on the DRAGON and HERMES codes — has successfully been used by the IceCube collaboration as a template in its discovery work of the neutrino diffuse emission of the Galaxy.
Remarkably, an updated version of the same model (KRAgamma Min) have been also found to correctly predict the gamma-ray counterpart of that emission as measured by LHAASO in the inner and outer Galactic Plane.
Taken together these findings points to the Cosmic Ray (CR) sea as the main origin of the gamma-ray and neutrino diffuse emissions favouring spatial dependent propagation to explain the high flux and spectral hardening towards the Galactic Center region.
Moreover we will show as those results provide a valuable insight on the CR Galactic population spectral shape in the knee region.
Recent ANTARES results and the perspectives of KM3NeT will be also discussed in this framework.Speaker: Dario Grasso (INFN Pisa) -
76
Recent IceCube Updates on Neutrino Emission from the Galactic Plane
IceCube has observed neutrino emission from the Galactic Plane. The initial observation, published in 2023, was enabled by a novel deep-learning-based cascade sample. This approach increased the effective area by around an order of magnitude at the relevant energies, providing the sensitivity needed to resolve the diffuse, extended signal.
Since then, IceCube has substantially improved its understanding of the Galactic Plane in neutrino light. This talk will cover IceCube's recent results on the Milky Way's neutrino emission: its energy and spatial distributions, its compatibility with emission models, its contribution to the total astrophysical neutrino flux, and the impact of updated data on the observation.
Speaker: Ludwig Neste (Stockholm University / Oscar Klein Centre) -
77
Neutrinos from the Galactic plane: modelling diffuse cosmic-ray emission and contribution from unresolved stellar clusters
The recent detection of Galactic neutrinos by the IceCube Observatory represents a major milestone for neutrino astrophysics. Existing model-dependent analyses, based on spatial and spectral templates reproducing the GeV Galactic diffuse γ-ray emission, have measured a diffuse Galactic neutrino component without resolving individual sources. In this contribution, I will present a novel theoretical computation of the expected neutrino emission from the Galactic Plane that, differently from previous models, includes both the diffuse emission produced by hadronic interactions of the cosmic-ray (CR) sea and the contribution from hadronic sources, namely young massive star clusters and supernova remnants, which are believed to dominate the production of Galactic CR protons. Particle acceleration is modeled at both the collective wind termination shocks of star clusters and supernova shocks. While the predicted neutrino flux from individual star clusters remains below the sensitivity of current cubic-kilometer detectors, their cumulative emission is expected to contribute to the unresolved Galactic diffuse component. Based on multiple synthetic realizations of the Galactic star cluster population, we derive new neutrino template maps under different assumptions for particle diffusion within clusters and the Galactic CR distribution. These templates are made publicly available for future neutrino analyses aimed at constraining the role of star clusters in extreme CR acceleration and Galactic neutrino production. The predicted normalization is consistent with the IceCube best-fit Galactic diffuse emission, suggesting that the unresolved contribution from star clusters may be significant.
Speaker: Stefano Menchiari (INAF - Osservatorio Astrofisico di Arretri) -
78
Can KM3-230213A be compatible with a cosmogenic origin?
On February 13, 2023 the KM3NeT/ARCA telescope observed a track-like event compatible with an ultra-high-energy muon with an estimated energy of 120 PeV, produced by a neutrino with an even higher energy, making it the most energetic neutrino event ever detected. The reported equivalent flux suggests the possible existence of a new diffuse component. A diffuse cosmogenic flux is expected to originate from the interactions of ultra-high-energy cosmic rays with ambient photon and matter fields. Here we show that this component can be compatible with the reported flux level only if the cosmogenic emission is integrated at least up to redshift ~$z = 6 $ and assuming a subdominant fraction of protons in the ultra-high-energy cosmic-ray flux, thus placing constraints on known cosmic accelerators.
These conditions impose constraints on known cosmic accelerators and open a window into an unexplored region of the Universe at this energy scale.Speaker: Antonio Condorelli (APC/CNRS)
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75
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3:45 PM
Coffe break
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Hardware and Software developments for HE astroparticle physics: 2 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
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79
The Pierre Auger Observatory Data Structure and Open Data
The Pierre Auger Observatory produces a rich and diverse collection of data that extends far beyond the raw measurements recorded by its detectors. In addition to the event data acquired by the Surface Detector, Fluorescence Detector, Underground Muon Detector and Radio Detector, the Collaboration continuously collects and manages a wide range of auxiliary datasets, including detector calibration, atmospheric monitoring, detector status and other metadata that are essential for event reconstruction and physics analyses. In this contribution, we present the data management infrastructure of the Pierre Auger Observatory, focusing on the organization, storage and access to the heterogeneous data products of the Observatory. We will discuss the architecture and services of the Auger Data Center, which ensure reliable long-term preservation and efficient access to these resources, supporting detector operations, event reconstruction and physics analyses. Finally, we will introduce the recent Open Data release. A carefully selected subset of the data of the Observatory has been made publicly available through simplified data formats and accompanying documentation, lowering the barrier to access for both educational purposes and introductory scientific analyses. This initiative enables students, educators and researchers to explore high-energy cosmic-ray data while promoting transparency, reproducibility and broader engagement with the scientific community.
Speaker: Emanuele De Vito (Istituto Nazionale di Fisica Nucleare) -
80
Performance of deep learning methods for the event reconstruction of CTAO Large-Sized Telescopes
Very-high-energy (VHE) gamma rays, with energies in the GeV-TeV range, are crucial for probing the most energetic phenomena in the universe. They are detected by Imaging Atmospheric Cherenkov Telescopes (IACTs), recording the Cherenkov light produced by VHE gamma rays or cosmic rays interacting with the atmosphere and enabling the reconstruction of the primary particle’s properties, including its type, energy, and arrival direction. The Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based gamma-ray observatory, designed to significantly improve the sensitivity of the current IACT observatories over an energy range from 20 GeV to 300 TeV.
In this contribution, we present the application of deep learning techniques to the reconstruction of simulated VHE data for the Large-Sized Telescopes (LSTs) of CTAO, considering both monoscopic and stereoscopic configurations. LST-1 is already in operation on La Palma, while LSTs 2–4 are currently under construction and will start operating in the near future. The analysis is performed within the CTLearn framework, designed to integrate deep learning methods into IACT event reconstruction, using pixel-wise camera data as input. The results obtained with CTLearn are evaluated and compared to standard analysis methods, based on image parametrization and machine learning techniques such as Random Forests. This study provides insight into the advantages and limitations of each approach and highlights the potential of deep learning techniques to enhance the scientific capabilities of current and future IACT arrays.
Speaker: Elisa Visentin (Istituto Nazionale di Fisica Nucleare) -
81
Exploring Ultra High Energy Cosmic Rays and Very High Energy Neutrinos with Orbital and Suborbital Facilities
Ultra-high-energy cosmic rays (UHECRs) and very-high-energy neutrinos (VHENs) remain among the most challenging messengers in astroparticle physics because of their extremely low fluxes and the large observational exposures required for their detection. Observations from suborbital and orbital platforms provide a unique opportunity to use the increase in target volumes to provide significant gains in exposures for both of these high-energy messengers while enabling the exploration of novel technologies specifically suited for space-based applications.
This contribution presents the current status of two complementary pathfinder missions that address these challenges from different observational regimes. Terzina, one of the payloads of the NUSES satellite mission, is designed to observe Cherenkov emission from extensive air showers developing near the Earth's limb, validating key technologies and observational strategies for future orbital missions dedicated to UHECR and Earth-skimming neutrino detection. The POEMMA-Balloon with Radio (PBR), an Ultra Long Duration Balloon experiment, extends this approach to a suborbital platform which combines a wide-field optical instruments with a radio detector, allowing measurements of atmospheric fluorescence, cherenkov emission and radio emission from extensive air showers, and providing a flexible testbed for multi-messenger observations from near space.
The complementary capabilities of these two pathfinders illustrate a coherent development roadmap toward next-generation space-based observatories. Their scientific objectives, detector concepts, and expected performance will be discussed, highlighting how coordinated developments in instrumentation, readout electronics, simulations, and reconstruction techniques contribute to establishing the experimental foundations for future multi-messenger observations of the highest-energy Universe.
Speaker: Caterina Trimarelli (Istituto Nazionale di Fisica Nucleare) -
82
Recent updates on the SiPM camera for the prototype Schwarzschild–Couder Telescope
The prototype Schwarzschild–Couder Telescope (pSCT), located at the Fred Lawrence Whipple Observatory, serves as a technological demonstrator for a future Imaging Atmospheric Cherenkov Telescopes to be proposed for a possible upgrade of the Cherenkov Telescope Array Observatory. Its innovative dual-mirror Schwarzschild–Couder optical design focuses shower images on a compact focal plane, which will consist of a high resolution Silicon Photomultiplier (SiPM) camera.
A major upgrade of the pSCT camera is currently underway. The new focal plane will be fully instrumented with 11,382 next-generation SiPM pixels, expanding the field of view from 2.7° to 8° while substantially improving photon detection efficiency, angular resolution, and gamma–hadron discrimination capabilities. This enhancement represents a significant advance in imaging performance, allowing more accurate reconstruction of air-shower morphology and increased sensitivity to both extended and low-surface-brightness gamma-ray sources.
Building on the successful detection of the Crab Nebula with a partially populated camera, the upgraded instrument will further demonstrate the scientific and technological advantages of the Schwarzschild–Couder concept for precision gamma-ray astronomy and multi-messenger astrophysics. In parallel, the adoption of new low-noise front-end electronics will lower the trigger threshold and improve the accuracy of event reconstruction. The combination of a wider field of view, enhanced photosensor performance, and optimized readout electronics will allow the pSCT to fully capitalize on its optical design while validating key technologies for future high-resolution gamma-ray observatories.
This contribution presents the current status of the camera upgrade, including SiPM production and characterization, module assembly and integration, commissioning strategy, and the expected performance of the fully upgraded instrument.
Speaker: Dr Leonardo Di Venere (INFN Bari) -
83
The Zirè payload onboard the NUSES space mission
NUSES is an Italian-led space mission, representing a novel scientific and technological pathfinder towards the detection of low and high energy radiation. The mission hosts two payloads: Terzina and Zirè. Terzina is designed to detect Cherenkov light from extensive air showers produced by ultra-high energy cosmic rays or Earth-skimming high energy neutrinos. Zirè will measure fluxes of Cosmic Ray protons, electrons and heavier nuclei up to 300 MeV, of solar and galactic origin. The instrument will detect transient photon sources (i.e. Gamma Ray Bursts) in the intriguing energy range of 0.1 to 30 MeV, as well as investigate possible correlations with seismic phenomena linked to the Magnetosphere-Ionosphere-Lithosphere Coupling, while simultaneously monitoring the variability of Van Allen belts. Equipped with state-of-the-art Silicon Photomultipliers as the optical readout of choice, Zirè integrates plastic scintillator bars and tiles, calorimetric crystals, and fiber tracker modules to deliver high photon detection efficiency across a wide dynamic range, paving the way for next-generation space-borne detectors. Additionally, the payload will be equipped with a Low-Energy Module in order to extend the overall sensitivity to electrons from 0.1 to 7 MeV and protons from 3 to 50 MeV.
This presentation outlines the current development status, instrument integration and performance characterization aspects of Zirè onboard the NUSES space mission. The main design framework is presented as the mission advances toward its launch, currently foreseen in 2027, featuring key detector novelties and performance evaluations both in laboratory and test beam campaigns, alongside a comprehensive overview of space readiness tests performed on both Qualification and Flight Models.Speaker: Mr Dimitrios Kyratzis (Gran Sasso Science Institute (GSSI) and INFN-LNGS)
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79
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H.E. astrophysical Neutrino detection: 2 Aula C
Aula C
Chemistry Department, University Sapienza
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84
Evidence for neutrino emission from X-ray-bright AGN with IceCube
The detection of TeV neutrinos from the nearby Seyfert galaxy NGC 1068 by IceCube challenges conventional multi-messenger paradigms: its neutrino flux exceeds the gamma-ray counterpart by approximately two orders of magnitude, contradicting expectations of correlated emission. This discrepancy points to neutrino production in optically thick environments near the supermassive black hole, such as the X-ray corona, where TeV gamma rays are absorbed. Motivated by NGC 1068's properties as one of the brightest X-ray Seyfert galaxies, IceCube performed targeted searches for similar sources. In this talk, we report on a recent analysis that searches 13.1 years of IceCube data for additional TeV-PeV neutrino emission from X-ray-bright AGN. We confirm NGC 1068 as the most significant extragalactic neutrino source at 4.0σ with consistent flux measurements. Extending the search to a newly compiled catalog of 47 X-ray-bright, non-blazar AGN selected from the Swift/BAT survey, we find evidence for population-level neutrino emission: a binomial test reveals a 3.3σ excess from an ensemble of 11 sources.
Speaker: Chiara Bellenghi (Technical University of Munich) -
85
A search for compact neutrino sources by combining KM3NeT/ARCA and ANTARES data
Neutrino telescopes are a fundamental tool to explore the most extreme and energetic phenomena in the Universe. The ANTARES detector in the Mediterranean Sea has played a pioneering role in deep-sea neutrino observations, collecting data for 16 years until 2022. The KM3NeT research infrastructure, a successor to ANTARES, is currently under construction at two sites in the Mediterranean Sea. In particular, KM3NeT/ARCA, the detector located offshore from Portopalo of Capo Passero, Sicily, was designed to significantly enhance sensitivity to high-energy astrophysical neutrinos.
This study analyses the combined dataset from ANTARES and the available KM3NeT/ARCA data, focusing on the detection of high-energy neutrinos from point-like sources and some with extensions up to a few degrees. A comprehensive catalogue including about 100 sources has been examined for potential neutrino emission: it includes prominent gamma-ray emitters, galactic gamma-ray sources with possible hadronic components (TeVCat), extragalactic AGNs with intense radio flux
detected by VLBI, and the most promising candidates previously investigated by IceCube and ANTARES.
This analysis demonstrates the potential of combining data from these neutrino detectors using a binned likelihood approach.Speaker: Sandra Zavatarelli (Istituto Nazionale di Fisica Nucleare) -
86
KM3NeT/ARCA stacking search for high-energy neutrino emission from blazars and ultra-luminous infrared galaxies
High-energy astrophysical neutrinos are expected to originate from powerful cosmic accelerators such as blazars and ultra-luminous infrared galaxies. Their cumulative emission can be investigated through a binned likelihood stacking analysis with KM3NeT/ARCA, a deep-sea Cherenkov neutrino detector currently under construction in the Mediterranean Sea. Its modular design enables partial operation and data acquisition during construction. This contribution presents a search based on 336 days of data collected with detector configurations comprising 19–21 detection units, corresponding to 1544 selected track-like neutrino candidates. The analysis targets three source populations: 75 ultra-luminous infrared galaxies, 232 high-synchrotron-peaked BL Lac objects, and 88 extreme blazars. Their expected neutrino fluxes are derived from numerical models constrained by multi-wavelength observational data. No statistically significant excess above the atmospheric background is observed for any catalogue, and 90% confidence level upper limits are set on their neutrino emission.
Speaker: Francesco Carenini (Istituto Nazionale di Fisica Nucleare) -
87
Predicting High-Energy neutrino emission from X-ray absorption in CSM-interacting SNe
Core-collapse supernovae interacting with a dense circumstellar medium (CSM) are promising sources of high-energy neutrinos. However, most existing neutrino predictions rely on specific assumptions about the CSM density profile and the progenitor mass-loss history. We develop a fully data-driven framework that directly connects X-ray observations to the expected neutrino emission. Using the observed temporal evolution of the X-ray absorbing column density, $N_{\rm H}(t)$, together with shock velocities inferred from X-ray temperatures, we reconstruct the CSM density profile, estimate the shock power, determine the shock breakout time, and calculate the resulting neutrino luminosity. We apply this method to the nearby interacting supernovae SN~2023ixf and SN~2024ggi, and compute the expected neutrino fluence and event rates for IceCube and KM3NeT/ARCA. We find that neutrino production is strongly concentrated around the shock breakout epoch, when the circumstellar column density is highest. Our results demonstrate that X-ray absorption measurements can be used to guide and optimize neutrino searches in interacting supernovae, providing an observationally driven framework for future multimessenger studies of shock-powered transients.
Speaker: Silvia Gagliardini (Istituto Nazionale di Fisica Nucleare) -
88
A Multimessenger Template-Fitting Analysis for Diffuse Galactic Neutrino Emission with KM3NeT/ARCA
KM3NeT/ARCA is a deep-sea neutrino detector in the Mediterranean Sea, off the coast of Sicily, designed to explore the high-energy neutrino sky with a final instrumented volume of about one cubic kilometer. It is currently under construction but already taking data in its partially deployed configuration.
Its location and water-Cherenkov detection technology provide an excellent view of the Southern sky and good angular resolution, making it particularly well suited for studies of extended Galactic neutrino emission.
We present a multi-messenger template-fitting analysis aimed at searching for diffuse Galactic neutrino emission with KM3NeT/ARCA data. The method compares the observed neutrino events with spatial and spectral templates derived from gamma-ray observations by experiments such as HAWC and LHAASO, as well as from numerical codes simulating the propagation of cosmic rays and their interaction with the interstellar gas, including the scenario of inhomogeneous galactocentric diffusion KRA-γ.
The analysis relies on an unbinned likelihood approach within a framework that allows us to study the morphological distribution of neutrino fluxes and provides a basis for future searches for diffuse Galactic neutrino emission with KM3NeT/ARCA.Speaker: Dr Antonio De Benedittis (Università degli studi della Campania "L. Vanvitelli" & Istituto Nazionale di Fisica Nucleare sez. Napoli)
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84
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Poster session: poster esposition and presentation
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89
Investigation of Cascade Fluctuations for Cosmic-Ray Energy Reconstruction Above 1 TeV
In the energy range above 1 TeV, direct measurements of cosmic-ray particle energies become highly challenging due to the need for massive calorimeters capable of fully absorbing the cascade of secondary particles. However, the strict mass and size limitations of space-borne experiments make the use of thin calorimeters, which register only the initial stage of cascade development, a promising alternative.
The proposed method for determining the energy of the primary particle is based on the analysis of correlation characteristics of cascade development. The main observables are the number of secondary particles at the observation level and the longitudinal cascade development parameter, defined as the difference between the numbers of particles recorded in successive absorber layers. The method relies on the quasi-universality of cascades initiated by primary particles of the same energy and mass.
The use of correlation dependencies significantly reduces the influence of cascade fluctuations and improves the accuracy of primary energy reconstruction compared to conventional analyses based on cascade curves. Simulation results demonstrate the possibility of determining particle energies in the range of 1–100 TeV with an energy resolution of about 10%, even when using an ultra-thin calorimeter.
The proposed technique can be applied in space experiments for the direct investigation of the energy spectrum and elemental composition of high-energy cosmic rays. A similar approach may also be used for energy determination of extensive air showers in ground-based experiments.
This research was supported by the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP22785312).Speaker: Anastasia Fedosimova -
90
Search for Cosmic-Ray Anisotropy Above 1 PeV Using Correlation Characteristics of Extensive Air Showers
This work investigates the anisotropy of cosmic-ray elemental groups using data from the KASCADE experiment. Particular attention is paid to the determination of primary particle energy and mass, which is complicated by fluctuations in the development of extensive air showers.
To reduce the influence of shower-to-shower fluctuations, a correlation method for primary particle parameter reconstruction is applied. The method is based on the analysis of cascade development characteristics and significantly improves the accuracy of primary energy and mass determination. In addition, it enables the analysis of individual air showers without substantial loss of precision.
The proposed approach exhibits low sensitivity to fluctuations of the cascade process and allows the simultaneous analysis of events detected over a wide range of zenith angles. This extends the statistical capabilities of the study and increases the reliability of anisotropy measurements.
Within this work, the distributions of right ascension and declination were investigated for five groups of primary nuclei: p, He, C, Si, and Fe. The analysis of KASCADE experimental data revealed differences in the distributions of individual elemental groups in the equatorial coordinate system, which may indicate the presence of anisotropic structures in cosmic-ray fluxes of different chemical compositions.
The observed features of the distributions may be associated with the influence of the nearest Galactic spiral arms and the structure of the Galactic magnetic field on the propagation of high-energy cosmic rays.
This research was supported by the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP22785312).Speaker: Sayora Ibraimova (Institute of Physics and Technology) -
91
Multi-Messenger Constraints on the Cosmogenic Origin of the KM3-230213A event
The KM3NeT Collaboration has discovered KM3-230213A, the highest-energy neutrino
event detected to date, with an estimated energy of ∼200 PeV and a likely astrophysical origin. In
this talk, we will investigate the possibility that KM3-230213A has a cosmogenic origin, namely that
it was produced by interactions of ultra-high-energy cosmic rays (UHECRs) with low-energy photons
during their extragalactic propagation. We will focus on the multi-messenger constraints set by the isotropic gamma-ray and neutrino
backgrounds arising from UHECRs, considering two different
scenarios. In the first, a primary proton population saturates the proton flux measured by the Pierre
Auger Observatory corresponding to the so-called low-energy (LE) component. In the second, the
high-energy scenario, a subdominant proton population contaminates the observed UHECR flux at
10% level. We will show that cascaded gamma rays strongly constrain the LE scenario: if the source
cosmological evolution is too strong, the predicted gamma-ray spectrum overshoots current Fermi-
LAT measurements, ruling out this explanation for KM3-230213A. On the contrary, the high-energy
scenario remains compatible with current cosmic-ray, neutrino, and gamma-ray data. Future
measurements of the UHECR composition will constrain this scenario, while new
constraints from neutrino telescopes will provide a crucial test of those from cosmic-ray
experiments, further highlighting the power of a multi-messenger approach.Speaker: Antonio Ambrosone (Istituto Nazionale di Fisica Nucleare) -
92
Detection of gravitational lensing in VLBA observations of IceCube high-energy neutrino counterpart blazars
The origin of high-energy cosmic neutrinos is still being controversially debated. We examined likely counterparts of high-energy cosmic neutrinos detected by the IceCube detector and analyzed their jet kinematics in high-resolution VLBA observations.
We identify signatures suggestive of gravitational lensing in the nuclear cores of four blazars: TXS 0506+056, PKS 0735+178, PKS 1717+177, and PKS 2233-148. PKS 0735+178 shows the most prominent morphological evidence. Four independent Neutrino Detectors (IceCube, Baikal, KM3NeT, Baksan) reported events from the direction of PKS 0735+178 in December 2021. Combined gravitational lensing and jet precession gradually impact different parts of the jet to be lensed and curved into rings of different sizes with time. A de-lensed source reconstruction with a point-mass lens model (𝑀 ∼ few ×106 M⊙ ) is applied. The pronounced curved and loop-like morphology observed in the image-plane distribution appear as an almost straight jet in the reconstructed source plane. Radio and 𝛾-ray variability correlate with times of loops and are most likely enhanced by gravitational lensing as well.
Although the neutrino-generating process is still not known, blazars - and gravitational lensing - might play an important role.Speaker: Silke Britzen (Max-Planck-Institut für Radioastronomie) -
93
Search for atmospheric millicharged particles with the IceCube Upgrade
Millicharged particles—hypothetical particles carrying a fraction of the elementary electric charge—arise in extensions of the Standard Model and can be produced in the Earth's atmosphere via meson decay and proton bremsstrahlung. We compute the resulting atmospheric fluxes and simulate the propagation of these particles through the Earth to the IceCube Upgrade. The IceCube Upgrade, a densely instrumented extension of the IceCube Neutrino Observatory designed to enhance sensitivity to low-energy events, provides new opportunities to search for the low-light signals expected from particles with small charges. We discuss the challenges associated with detecting such faint signatures, including ongoing efforts toward a dedicated trigger. This work establishes the simulation framework required to evaluate the sensitivity of the IceCube Upgrade to atmospheric millicharged particles.
Speaker: Louise Lallement Arnaud (Université libre de Bruxelles) -
94
Leptonic portals to energetic neutrinos and their propagation through the cosmic backgrounds: new Monte Carlo frameworks
Energetic fluxes of gamma rays and neutrinos, beyond $10^{18}\,\mathrm{eV}$, are predicted in standard cosmogenic paradigms and from the decay of heavy dark matter candidates. After their production, they need to travel cosmological distances before reaching the Earth. During their propagation through the cosmic backgrounds, several additional effects can arise, altering the prompt energy spectra. For instance, extremely energetic gamma rays propagating through pervasive low-energy radiation could produce decaying heavy leptons and hadrons, ultimately leading to leptonic neutrino production. These processes could alter the expected gamma-ray and neutrino fluxes in both hadronic and leptonic production scenarios. Furthermore, such energetic neutrinos produced at cosmological distances also need to propagate through the cosmic neutrino and microwave backgrounds, potentially triggering hadronic cascades. At the source, leptonic production of neutrinos could take place in the cores of active galactic nuclei, where multi-TeV gamma rays interact with X-ray photons from the hot corona, as investigated in the context of the IceCube detection of NGC 1068. We explore the above scenarios within the CRPropa Monte Carlo framework, developing dedicated tools to account for high-centre-of-mass leptonic interactions, neutrino--neutrino and neutrino--photon scatterings, decay of heavy leptons and hadrons, and the full treatment of final hadronic states. In particular, decays and hadronisations are performed in synergy with the PYTHIA event generator. With these novel and detailed tools, we characterise the observables related to these uncommon processes in extreme scenarios, paving the way to forthcoming refined studies.
Speaker: Gaetano Di Marco (Madrid Autonomous University (UAM) and Institute for Theoretical Physics (IFT UAM-CSIC)) -
95
2012-2026: ICECUBE data:: Are they probing anyway an UHE atmospheric intrinsic charm emergence?
Since 2013 the ICECUBE neutrino PeV cascade suggested the first finger-print of the desired new neutrino astonomy. The consequent Tau double bangs neutrino were obbviously much expected, 2014 (a). But since 2015 up to2017 ICECUBE published a deep statistical article showing an absence of Tau double trace (b). Indeed ICECUBE had shown that muon and electron neutrino flavor signature were at same rate (b), suggesting a charmed atmospheric signal. However since 2018 up to 2025 ICECUBE declared two possible tau double bang event, confirming anyway their paucity respect their "democratic" expected presence in cosmic mix flight. On very recent article (2024), confirmed on 2026 (c) ICECUBE updated by indirect signals to a total of seven tau event , apparently consistent to an astronomy but even so, better tuned to atmospheric charmed secondaries as we shall show. We remark that the up-date ICECUBE highest energy data, 2011-2026 show:
1) The missing of any UHE neutrino self clustering,
2) The missing UHE neutrino-gamma connection (past or recent)
3) The missing among three hundred alert events, of any-gamma trace
4) The remarkable paucity of up muon tracks versus very rare down ones
5) The presence of the "muon puzzle" at ten TeV-PeVs ICECUBE energy
6) The absence of correlation with brightest gamma as huge GRB221009A.
7) The clear tau double bangs paucity agrees with charmed ones.
After many more ICECUBE data , we are still convinced (d) that highest energy ICECUBE neutrino are pointing to an important atmospheric intrinsic charmed presence (e) ,much more than, an ever dreamed , Neutrino sky Astronomy.Speaker: Daniele Fargion -
96
Energy Scale Calibration of HEPD-02 with Applications to Helium Flux Studies in Low Earth Orbit
The High Energy Particle Detector (HEPD-02), onboard the China Seismo-Electromagnetic Satellite (CSES-02), has been operating since June 2025. It measures protons (30–200 MeV), electrons (3–100 MeV) and light nuclei for cosmic ray, geophysical and space weather studies. This detector features an innovative MAPS-based tracker (Monolithic Active Pixel Sensors), a calorimeter of plastic scintillators and LYSO bars, and a dual High Gain/Low Gain (HG/LG) readout electronics. This contribution summarises a full data-driven strategy for the calibration of the detector using both test beam and flight data, as a complementary approach to the MC-based one. The read-out response, including non-linear scintillation quenching effects, as well as the position-dependent light-collection efficiency of the 64 photomultipliers has been characterised. This enables a full determination of detector energy scale over several orders of magnitudes, improving the accuracy of both the event reconstruction and of the HEPD-02 MC simulation. The preliminary performance of this new reconstruction on the measurement of Helium fluxes in LEO (Low Earth Orbit) will be discussed.
Speaker: Leonardo Gioacchini (Istituto Nazionale di Fisica Nucleare - TIFPA) -
97
Direct measurement of the ionization response of liquid argon to low-energy nuclear recoils with the ReD experiment
The detection of low-mass Dark Matter candidates in dual-phase liquid argon (LAr) Time Projection Chambers (TPCs) heavily depends on the ionization channel, as primary scintillation is barely detectable at few-keV recoil energies. In such a regime, a precise characterization of the ionization yield $Q_y$ (defined as the number of ionization electrons per unit of energy deposited in liquid argon) is thus a crucial requirement to calibrate the detector response.
In this contribution, we report the final, model-independent measurement of $Q_y$ for argon nuclear recoils in the 2–10 keV range, obtained with the Recoil Directionality (ReD) apparatus, installed at INFN - Sezione di Catania. The experimental strategy consisted in irradiating a compact ($5 \times 5 \times 6$ cm$^3$) dual-phase LAr TPC with a neutron beam from a $^{252}$Cf source. Signals were acquired by cryogenic SiPMs, while recoil energies were reconstructed on an event-by-event basis via two-body kinematics, measuring the neutron time-of-flight and scattering angle.
Our results extend the experimental coverage below the previous threshold of $\sim7$ keV, with the measured ionization yield showing an increase at the lowest energies. The total uncertainty is constrained between 4.3% and 5.7%, mainly due to the systematics on the ionization gain $g_2$ (a detector-specific parameter representing the average response produced by a single electron).
Finally, we discuss the ongoing upgrade ReD+, currently operating at INFN - Laboratori Nazionali del Sud, designed to extend the measurement into the sub-keV regime using both a $^{252}$Cf source and a deuterium-deuterium neutron generator.Speaker: Gioacchino Alex Anastasi (Università di Catania & INFN Catania)
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89
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8:00 PM
Conference Dinner: it will be served at the Restaurant "Consolini", via Marmorata 28, Roma. Bus will depart at 7:30 PM from Piazzale Aldo Moro (University entrance) and return to Piazzale Aldo Moro after dinner.
The Conference Dinner will be served at the Restaurant "Consolini", via Marmorata 28, Roma. Bus will depart at 7:30 PM from Piazzale Aldo Moro (University entrance)
and return to Piazzale Aldo Moro after dinner.
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Plenary: 8 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Chair Aldo Morselli
Convener: Prof. Nicolao Fornengo (Istituto Nazionale di Fisica Nucleare)-
98
A concordance picture of Tidal Disruption Events
A tidal disruption event (TDE) occurs when an ill-fated star ventures too close to a black hole. The intense gravitational forces of the black hole rip the star apart, sending roughly half of its mass hurtling into space, while the remainder falls back toward the black hole. This process produces a rich, multiwavelength observational signature—typically including an optical and ultraviolet flare lasting several months, accompanied by both prompt and delayed X-ray emission, and occasionally, a radio signal. Recent advances in theoretical models and, in particular, the consensus results of several simulations have significantly reshaped our understanding of the mechanisms behind TDE emission. In this talk, I will present key observational findings and explore how our perspective has evolved from earlier interpretations to current insights. I will discuss, in particular, possible high-energy multi-messenger signals from TDEs.
Speaker: Tsvi Piran (he Hebrew University, Jerusalem) -
99
Ultraviolet and neutrino emission from CCSNe (Core collapse Supernovae) in CSM (circumstellar medium) scenario
Massive stars (>8 Msun) often undergo intense mass loss through winds or eruptive events in the final stages of their evolution, leading to the formation of a dense circumstellar medium (CSM). This material, expelled months to years before core collapse, shapes the pre-supernova environment and influences the early emission. One key phase is the shock breakout (SBO), when the outgoing radiation-mediated shock reaches the stellar surface and releases a brief X-ray/UV flash. If dense CSM is present, the interaction can extend the emission into the UV/optical bands, as seen in Type IIn supernovae. Fast blue optical transients (FBOTs) may represent extreme cases of this interaction, possibly linked to more compact or massive CSM. Recent events such as SN~2023ixf and SN~2024ggi confirm the relevance of dense environments and highlight the value of UV observations. In this work, we model SBOs in CSM to estimate the maximum detection horizons for future UV missions like ULTRASAT, as well as potential neutrino signals detectable by IceCube and KM3NeT. We also assess expected detection rates and discuss the prospects for observing such events in the near future within a multi-messenger framework
Speaker: Prof. Dafne Guetta (Ariel University, Ariel)
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98
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10:30 AM
Coffee Break
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Plenary: 9 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Chair Aldo Morselli
Convener: Dr Juergen Brunner (CPPM)-
100
Status on the P-ONE experiment
The Pacific Ocean Neutrino Experiment (P-ONE) is a planned km³-scale neutrino telescope leveraging Ocean Networks Canada’s deep-sea optical fibre infrastructure. The experiment’s objectives include high-precision angular resolution for neutrino source searches, flavour-sensitive measurements of the diffuse neutrino flux, and the delivery of complementary marine science data.
The first detector string, P-ONE-1, reached several significant milestones in 2026, spanning the full integration chain from individual sensor assembly to complete detector line integration and preparation for sea deployment. Sensors were tested at each stage of the integration process, with the line’s slow and fast control systems developed in parallel.
This talk will briefly present the initial challenges encountered in the deep-sea environment, the mitigation strategies developed in response, and preliminary performance benchmarks from hardware and software testing of the detector line. It will conclude with an outlook on the commissioning of the line in water and the measurement plan after deployment.
Speaker: Vincent Gousy-Leblanc -
101
PUEO status report and perspectives
The Payload for Ultrahigh Energy Observations (PUEO) is an experiment that flies under NASA’s long-duration Antarctic balloon program searching for ultra-high energy neutrinos using the radio Cerenkov technique. It is the successor to the NASA-funded ANITA experiment that took four flights over Antarctic ice between 2006 and 2017. PUEO flew for 23 days during the 2025-2026 Antarctic summer season. Both experiments flew an array of broadband antennas at approximately 40km altitude where they scanned over a million square kilometers of ice within their horizon to search for impulsive radio signals induced by neutrino interactions in the ice. Both experiments are also sensitive to geomagnetic radio signals from cosmic ray interactions interacting in the atmosphere, sometimes after a reflection of the signal from the surface of the ice. PUEO included a novel threshold-lowering trigger and an additional antenna array that was deployed in-flight for increased sensitivity to low-frequency signals expected from cosmic ray interactions as well as air showers induced by tau neutrinos. I will discuss the in-flight performance of the PUEO instrument and progress made so far on analysis of its world-class dataset.
Speaker: Amy Connolly (UCL) -
102
Listening to the high energy universe
Acoustic detection has been suggested in late 1950’s as a complementary technique for extending research on neutrino astronomy into the ultra-high-energy region above 10^18 eV, where the expected fluxes are too low to be efficiently observed by km3-scale Cherenkov underwater or under-ice detectors. The method is based on the thermo-acoustic effect proposed by Askaryan, according to which the energy deposited by a neutrino-induced hadronic cascade generates a localized heating of the medium and the emission of a coherent bipolar pressure pulse with characteristic frequencies of a few tens of kHz. Recent observation of an ultra-high-energy neutrino candidate by KM3NeT has renewed interest in acoustic detection as a possible route toward the observation of cosmogenic neutrinos.
INFN is playing a pioneering role in the development of this technique establishing some of the first permanent deep-sea acoustic observatories dedicated to the characterization of the underwater acoustic environment and the study of neutrino-like signals. The INFN cabled infrastructures offshore Catania and Capo Passero – where the KM3NeT-ARCA detector is deployed- provide exceptional experimental laboratories for the development of acoustic sensors, real-time acquisition systems, acoustic positioning techniques and advanced signal-processing methods.
In this contribution, we review the scientific motivations highlighting the added value provided by the available marine infrastructures and novel sound detection techniques, that foster promising future for acoustic neutrino detection.
Speaker: Giorgio Maria Riccobene (Istituto Nazionale di Fisica Nucleare) -
103
The observation of KM3-230213A, implications and possible scenarios
The KM3NeT collaboration recently reported the observation of a horizontal track associated with a neutrino of ~220 PeV, the most energetic neutrino so far recorded. Such events can be produced when ultra-relativistic cosmic-ray protons or nuclei, emitted in the extreme astrophysical conditions, interact with matter or photons. While the cosmic neutrino energy spectrum measured up to date falls steeply with energy, the flux inferred by this event breaks the power law obtained in the TeV-PeV regime with a hardening above those energies. This suggests that the neutrino may have originated in a different cosmic environment than the lower-energy neutrinos, or this may be the first detection of a cosmogenic neutrino, resulting from the interactions of ultra-high-energy cosmic rays with background photons in the Universe. Based on this assumption, this event can be a signature of the furthest cosmic accelerator so far observed in this energy range. Different scenarios made to explain it will be treated in this talk.
Speaker: Antonio Marinelli (Istituto Nazionale di Fisica Nucleare)
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100
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1:00 PM
Lunch Break
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Direct Dark Matter detection: 1 Aula C
Aula C
Chemistry Department, University Sapienza
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104
From dark matter to neutrinos: the physics reach of dual-phase xenon TPCs
Dual-phase xenon TPCs have been at the forefront of direct dark matter detection for the last two decades. Originally designed to search for weakly interacting massive particles through nuclear recoils, continuous improvements in radioactive background reduction, detector mass, and signal reconstruction have transformed these detectors into versatile observatories for rare-event physics. Among the most exciting recent developments are the observations of solar neutrinos, including coherent elastic neutrino-nucleus scattering from
88B neutrinos and elastic neutrino-electron scattering from pp solar neutrinos. Their broad dynamic range also enables studies of rare weak processes involving xenon isotopes, such as double electron capture, double beta decay, and other second-order weak decays. In this talk, I will review the developments that have established dual-phase xenon TPCs as a unique experimental platform for both dark matter and neutrino physics, and I will discuss the prospects for the next generation of detectors.Speakers: Chiara Capelli (Sapienza University of Rome), Chiara Capelli (University of Zurich (UZH)) -
105
Darkside-20k experiment for dark matter searches
The DarkSide-20k experiment is a next-generation direct dark matter search currently under construction at the INFN Gran Sasso National Laboratory (LNGS). It is designed as a low-background dual-phase liquid argon time projection chamber using 50 tonnes of underground argon as the target mass, instrumented with large-area silicon photomultiplier (SiPM) arrays for scintillation-light detection. The detector is surrounded by active veto systems and is being developed with the goal of reaching a nearly background-free exposure for the search for Weakly Interacting Massive Particles.
This talk will present the main physics goals of DarkSide-20k, the key elements of the detector design, the role of underground argon and SiPM-based photosensors, and the status of the construction and integration activities. The expected sensitivity to high- and low-mass dark matter candidates will also be discussed, together with the main technological challenges addressed by the collaboration.Speaker: Dmitrii Rudik (Istituto Nazionale di Fisica Nucleare) -
106
XENONnT latest results: Solar pp neutrinos. 8-B neutrinos via CEvNS and more
XENONnT is a low-background experiment for direct dark matter searches at Laboratori Nazionali del Gran Sasso (INFN, Italy). Filled with 5.9 tonnes of instrumented target liquid xenon, the detector searched for WIMPs collecting science data for a total exposure of 6.5 tonne x years benefiting from excellent background conditions improving across time. New constraints on WIMP–nucleon scattering cross-section above 10 GeV/c have been obtained, yielding the strongest sensitivity and limits achieved by the experiment. In addition, thanks to the large exposure and ultra-low background, XENONnT has measured Boron-8 solar neutrinos via coherent elastic neutrino–nucleus scattering (CEvNS). Using data from the first three science runs, a search for Boron-8 solar neutrinos rejects the background-only hypothesis at 3.3 sigma.
In this talk I will review the new constraints on WIMP–nucleon scattering interactions and will discuss the Boron-8 solar neutrinos detection and the implications on CEvNS beyond-Standard-Model neutrino physics and light dark matter in the neutrino fog. I will finally briefly discuss the detector upgrades recently implemented and the outlook for the future science runs detector sensitivity.Speaker: Carla Macolino (Istituto Nazionale di Fisica Nucleare) -
107
BULLKID-DM: direct detection of light WIMP dark matter with a monolithic array of KID detectors
BULLKID-DM is a new experiment designed to search for low-mass WIMP-like dark matter particles (1 GeV/c2 or below) with nucleon cross-sections below 10−41 cm2. The detector consists of an 800 g array of over 2000 silicon dice, each acting as a particle absorber instrumented with multiplexed Kinetic Inductance Detectors (KIDs). Background rejection is achieved through a fully active structure, enabling fiducialization and anticoincidence techniques. A 20 g prototype, consisting of 60 voxels diced from a 3” silicon wafer, demonstrated the feasibility of this approach. Following its success, we present the first operation, in a surface laboratory equipped with a lead and copper radiation shield, of a 60 g demonstrator with 180 dice.
We also discuss ongoing R&D activities, including low-radioactivity detector mounting, a cryogenic scintillating veto readout with KIDs, in situ calibration techniques, and detector upgrades such as KIDs with dedicated phonon collecting structures and germanium substrates for multi-target capabilities.
Finally, we outline the deployment plan of the setup at the Gran Sasso underground laboratory (LNGS). The demonstrator will be installed at LNGS, in the new cryo-platform, by late 2026. Following successful validation, the full experiment is expected to be commissioned in 2028.Speaker: Angelo Cruciani (Istituto Nazionale di Fisica Nucleare) -
108
Dark Matter searches with the annual modulation signature: status and prospects
The annual modulation expected from the motion of the Earth around the Sun provides a distinctive signature for the direct detection of Galactic dark matter. The positive observation reported by DAMA/LIBRA has motivated an extensive experimental programme aimed at investigating this signal using the same target material, NaI(Tl). In this talk, I will review the historical development and current status of annual-modulation searches, with particular emphasis on the completed DAMA/LIBRA, ANAIS-112 and COSINE-100 experiments. Future prospects will also be reviewed, including efforts to achieve lower energy thresholds and background levels, such as SABRE North and South, COSINE-100U and COSINE-200, as well as complementary techniques such as COSINUS, which combines phonon and scintillation-light measurements in cryogenic NaI detectors. Finally, I will discuss the importance of accurately characterizing the detector response to nuclear recoils for the interpretation and comparison of experimental results.
Speaker: Martinez Maria (Universidad de Zaragoza)
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104
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Gravitational Waves detection: 1 Aula A
Aula A
Chemistry Department, University Sapienza
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109
The Virgo Upgrade Project: advancing detector sensitivity for future observations
The presentation will provide an overview of the Virgo Upgrade Project, highlighting the main improvements planned for the detector. Particular attention will be given to the technological innovations aimed at improving the interferometer’s sensitivity throughout the full detection band. The expected sensitivity performance and target curves will be discussed in the context of the detector’s current capabilities.
Speaker: Alessio Rocchi (Istituto Nazionale di Fisica Nucleare) -
110
The Lunar Gravitational-wave Antenna
The Lunar Gravitational-wave Antenna (LGWA) was proposed in 2020 as a decihertz GW detector concept. It utilizes the elastic response of the Moon to GWs, which leads to measurable displacements of the lunar surface. In this talk, we present the status of the LGWA project and present some highlights of recent collaboration works.
Speaker: Francesco Iacovelli (Johns Hopkins University) -
111
Wavefront Sensing and Optical Aberration Mitigation for Advanced Virgo and Beyond
The control of optical aberrations is one of the key challenges for the operation of current and future gravitational-wave detectors. In Advanced Virgo, the Thermal Compensation System (TCS) played a fundamental role in correcting both static optical imperfections and thermal effects induced by the circulating laser power, contributing to the stable operation of the interferometer.
In view of the forthcoming observing run O5, the Thermal Compensation System is being updated to cope with the new Advanced Virgo configuration featuring stable recycling cavities. Alongside the corresponding updates to the TCS optical layout, ongoing studies are exploring new approaches for TCS tuning, leveraging the operational experience gained with Advanced Virgo.
In this contribution, we present the thermal compensation strategy developed for the O5 upgrade, describing the main design choices, the implementation roadmap, and the expected impact on interferometer performance. We also discuss how the lessons learned from Advanced Virgo are driving the development of next-generation thermal compensation systems, highlighting the research and development activities currently underway for post-O5 upgrades and future observatories such as Einstein Telescope.Speaker: Ilaria Nardecchia (Istituto Nazionale di Fisica Nucleare) -
112
Towards quieter mirrors for gravitational-wave astronomy
The sensitivity of ground-based gravitational-wave interferometers is strongly linked to the performance of their core optics. In the most sensitive frequency region, coating thermal noise represents one of the fundamental limitations for present detectors and for future observatories aiming at a substantial improvement in astrophysical reach.
Current detectors such as Virgo and LIGO rely on highly reflective amorphous multilayer coatings which provide excellent optical performances but leave limited margin for the next sensitivity upgrades. Future instruments, including future upgrades of Virgo and the Einstein Telescope, require a coordinated reduction of coating mechanical losses, improved optical uniformity and optical absorption control, together with larger beam sizes, new substrates and, for low-frequency detectors, cryogenic operation.
This contribution will present an overview of coating-related challenges for current and next-generation gravitational-wave detectors, with emphasis on the experimental capabilities being developed at Tor Vergata to support future low-noise coating R&D within the broader framework of the Virgo and Einstein Telescope development roadmap.
Speaker: Diana Lumaca (INFN Sezione di Roma Tor Vergata) -
113
Quantum effects in future GW interferometers
Gravitational-wave detectors (GWDs) are capable of measuring extremely small variations in the relative distance between test masses induced by perturbations of spacetime. Their sensitivity is so high that quantum vacuum fluctuations become a significant noise source, known as quantum noise, limiting detector performance across most of the observation band.
Over the last decade, starting with the third observing run, GWDs have improved their sensitivity through the use of squeezed vacuum states, specially engineered quantum states of light that reduce the fluctuations affecting the measurement and thus improve detector sensitivity. Achieving broadband quantum-noise reduction, however, requires combining squeezed vacuum states with long filter cavities that provide the necessary frequency-dependent manipulation of quantum fluctuations.
This talk will introduce the origin of quantum noise and the strategies developed to mitigate it, presenting the results achieved in current detectors and focusing in particular on the solutions being adopted for the future Einstein Telescope. It will also show how the requirements for broadband quantum-noise reduction have become a key driver of the detector design, shaping not only its optical configuration but also the overall infrastructure of the observatory.Speaker: Valeria Sequino (ROMA2)
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109
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Searches for Extragalactic sources: 1 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
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114
Recent highlights on GRB physics with Ferm
Since its launch in 2008, the Fermi Gamma-ray Space Telescope has revolutionized the study of gamma-ray bursts (GRBs), through the unique synergy of the Gamma-ray Burst Monitor (GBM) and the Large Area Telescope (LAT), providing continuous coverage over more than seven decades in energy. This talk will review some of the most significant recent results from the Fermi mission, with particular emphasis on exceptional events such as GRB 221009A and on the important role of GRBs in the era of multi-messenger astrophysics. I will discuss the implications of these observations for our understanding of particle acceleration, radiation processes, and the physics of relativistic outflows.
Speaker: Sara Cutini (Istituto Nazionale di Fisica Nucleare) -
115
Detection of a second jet within the core of Mrk 501
We searched for blazars having a close pair of supermassive black holes within the radio core, making use of the extensive 15 and 43 GHz VLBA observations. This has led to detection of a second jet and its motion within the nucleus of Mrk 501. We find the jet motion to be consistent with orbital motion of a supermassive black hole binary with its orbital plane precessing. Assuming equal masses, we estimate the two components of the SMBBH to be separated by 27–128 Schwarzschild radii and each having a mass of 10^8 - 10^9 M⊙ . Its potential gravitational wave signal of 8 × 10−8 Hz falls within the expected frequency window detectable with the Square Kilometer Array (SKA) via pulsar timing experiment (10−9–10−7 Hz), assuming the feasibility of monitoring a large number of pulsars (> 20) for more than 10 years (Acosta-Pulido et al. 2015) with adequate timing precision.
Speaker: Silke Britzen (Max-Planck-Institut für Radioastronomie) -
116
Photon searches at the Pierre Auger Observatory
With its large exposure and the combination of different detection techniques, the Pierre Auger Observatory provides a unique sensitivity to ultra-high energy photons. Present results cover an energy range of more than three orders of magnitude, from 50 PeV to highest energies. In this contribution, the status of photon searches at the Pierre Auger Observatory is summarized, and implications are discussed. An outlook is given to Phase II of the Observatory where the recently upgraded detectors lead to an improved sensitivity to photon showers.
Speaker: Markus Risse -
117
Constraints on the intergalactic magnetic from Fermi-LAT observations of GRB 221009A
The observation of delayed GeV emission after a Gamma Ray Burst (GRB) detected at the very-high energies (VHE) beyond 100 GeV could indicate a non-zero magnetic field in the intergalactic medium. Indeed, VHE photons interact with the Extragalactic Background Light (EBL) to produce electron-positron pairs, which in turn can initiate electromagnetic cascades. An intergalactic magnetic field (IGMF) would deflect the pairs, leading to a delay of this emission, a so-called pair echo. The VHE detection of GRB221009A with LHAASO at several TeV offers a unique opportunity to probe the IGMF. Here we use the reported LHAASO VHE spectrum and CRPropa Monte Carlo simulations to generate time and energy dependent predictions of the cascade for different IGMF strengths in the Fermi/LAT energy domain. Using these predictions, we search for the pair echo using the full Poisson likelihood information. Depending on the modeling of the astrophysical afterglow emission of the GRB, we are able to set new constraints on the IGMF strength, reaching as low as 2.5e-17 G.
Speaker: Paolo Da Vela -
118
A time-resolved, systematic approach to gamma-ray burst physics
The Fermi mission observes Gamma-Ray Bursts (GRBs) over a broad energy range through its two instruments, the Gamma-ray Burst Monitor (GBM) and the Large Area Telescope (LAT), which operate in distinct yet complementary energy bands spanning from ~10 keV to >300 GeV. A joint spectral analysis of GRBs simultaneously detected by both instruments enables a comprehensive characterization of their prompt emission across this wide energy range, allowing for detailed studies of spectral evolution. Since the launch of Fermi, several catalogs based on single-instrument analyses have been published. However, only a few joint time-integrated studies combining GBM and LAT data are available, and these are based on relatively small samples.
In this contribution, we present the first comprehensive systematic spectral analysis of the complete sample of GRBs jointly observed by GBM and LAT over the first 17 years of the Fermi mission. The analysis is performed within the Multi-Mission Maximum Likelihood (3ML) framework, and includes both time-integrated and time-resolved studies. The sample comprises ~200 GRBs spanning a wide range of durations, fluences, and spectral properties, providing a representative dataset for statistical studies of prompt emission. We report preliminary results from the joint fits and quantitatively evaluate the impact of high-energy emission on the spectral parameters, including systematic shifts in the inferred values and a reduction in their uncertainties compared to previous results reported in the literature, as well as their evolution across time bins. We also investigate the presence of additional spectral components required to account for emission at the highest energies, such as extra power-law components or possible high-energy exponential cutoffs. By exploiting Fermi’s broadband coverage, this study provides new constraints on the physical mechanisms driving GRB prompt emission.
Speaker: Aldana Holzmann Airasca (Istituto Nazionale di Fisica Nucleare) -
119
Investigating the origin of the X-ray emission from blazars through multiwavelength polarimetry
The Imaging X‑ray Polarimetry Explorer (IXPE) has opened a new observational window on relativistic jets by providing the first X‑ray polarization measurements. These data offer a powerful diagnostic of jet composition, magnetic‑field geometry, and particle acceleration mechanisms. I will present recent IXPE results for blazars and radio galaxies and how in several cases those challenge long‑standing assumptions about the structure of the emitting region and jet composition.
Speaker: Ioannis Liodakis (Institute of Astrophysics - FORTH)
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114
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3:48 PM
Coffee break
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Searches for Extragalactic sources: 2 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
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120
Recent results in the arrival-direction analyses with the Pierre Auger Observatory
The Pierre Auger Observatory is the largest instrument currently operating for the detection of ultra-high-energy cosmic rays (UHECRs), whose origin is still one of the unsolved problems in astroparticle physics. Because UHECRs are predominantly charged particles, their propagation is influenced by Galactic and extragalactic magnetic fields, causing their arrival directions to deviate from the locations of their sources.
The analysis of events recorded during Phase I of the Pierre Auger Observatory, spanning the period from January 2004 to December 2022 and corresponding to a total exposure of $135{,}000$ km$^2$ sr yr, has yielded several important results.
A first key finding is the observation of a dipolar anisotropy in right ascension for events with energies above 8 EeV (1 EeV = $10^{18}$ eV), detected with a significance of $6.8\sigma$ relative to the isotropic expectation. The dipole points approximately $110^\circ$ away from the Galactic Center, providing strong evidence that cosmic rays at these energies are mainly of extragalactic origin.
A second significant result is the identification of an excess of events above 38 EeV within a circular region of $27^\circ$ radius centered on Centaurus A, with a significance of $4.0\sigma$. This localized excess is responsible for the observed indication of a correlation between UHECR arrival directions and a catalog of starburst galaxies, reaching a significance of $3.8\sigma$.
In this contribution, we review the latest results obtained from arrival-direction studies carried out with the Pierre Auger Observatory.Speaker: Lorenzo Apollonio (Unimi & INFN-Milano) -
121
The H.E.S.S. Transient Follow-up System in the Era of Multi-Messenger Astronomy
The field of time-domain and multi-messenger astronomy has undergone a profound transformation with the advent of large-scale survey instruments and real-time alert networks. The increasing number of transient events detected across the electromagnetic spectrum, together with alerts from neutrino and gravitational-wave observatories, requires rapid and efficient follow-up capabilities to maximise scientific return.
The rapid growth of time-domain and multi-messenger astronomy has created a need for efficient follow-up of transient events across a wide range of observatories. To address this challenge, the High Energy Stereoscopic System (H.E.S.S.), taking data in Nambia since 2003 and composed of five Imaging Atmospheric Cherenkov Telescopes (IACTs), operates a dedicated transient follow-up framework capable of responding autonomously to alerts from gamma-ray, neutrino, gravitational-wave, and other facilities.
In this talk, I will present the design and operation of the H.E.S.S. transient follow-up system, including how alerts are received, evaluated, and translated into follow-up observations. Examples from recent follow-up campaigns will illustrate the system's performance and its contribution to multi-messenger science.Speaker: Manuela Vecchi -
122
Time-resolved spectral catalog of gamma-ray bursts detected by Fermi-GBM in 16 years of mission
The Fermi Gamma-Ray Space Telescope, launched in 2008, was designed for the detection of the electromagnetic radiation in the energy range from 8 keV to 300 GeV, allowing for the study of many different types of galactic and extragalactic sources. In particular, the Gamma-Ray Burst Monitor (GBM) is the most prolific gamma-ray burst (GRB) detector to date, with more than 4300 observed events so far. Many publications dedicated to single GRBs and general catalogs have allowed us to reveal the temporal and spectral properties of these fascinating events.
Here we present a systematic analysis of a subsample of bright GRBs detected by GBM between 2008 and 2024, focusing on the temporal evolution of the parameters of the spectral models fitted to the data. This work is meant to update the official GRB time-resolved spectral catalog provided by the Fermi-GBM collaboration. The lightcurves are divided into time bins using the Bayesian Blocks method, whereas the time-resolved spectral analysis is done using the latest dedicated toolkit Gamma-Ray Data Tools (GDT). For each bin, different spectral models are fitted to the data, and the best one is selected through appropriate statistical criteria. We illustrate the different analysis phases, the values and distributions of the best model fit parameters, as well as studies on peak energy evolution trends and on cosmological quantities.Speaker: Davide Depalo (Istituto Nazionale di Fisica Nucleare - Sezione di Bari) -
123
Broadband modeling of the intranight variability of BL Lacertae during its 2022 outburst
Blazars dominate the extragalactic gamma-ray sky owing to relativistic boosting in jets closely aligned with our line of sight and to their persistent ability to accelerate particles to relativistic energies.
Between September and November 2022, the archetype blazar BL Lacertae exhibited one of its brightest gamma-ray flares to date, along with a major multi-wavelength outburst. A dedicated campaign from radio to very high-energy gamma rays closely followed the evolution of the source state across the flare. The first Large-Sized Telescope (LST-1) of the Cherenkov Telescope Array Observatory (CTAO) participated in the campaign and detected intranight variability with flux-doubling timescales as fast as 8 minutes, along with flux levels up to 4.4 Crab units above 100 GeV.
In this contribution, we present the characterization of the gamma-ray and multi-wavelength emission of BL Lac during this high state. We investigate the broadband evolution of the source emission across the flare within a time-dependent leptonic two-zone framework, in which the minute-scale intra-night variability is interpreted as arising from magnetic reconnection in a compact region closely oriented with the line of sight.Speaker: Davide Cerasole (Istituto Nazionale di Fisica Nucleare)
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120
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Gravitational Waves detection: 2 Aula A
Aula A
Chemistry Department, University Sapienza
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124
The Einstein Telescope: challenges and opportunities of a third-generation detector
The Einstein Telescope (ET) is a European project for a third-generation gravitational-wave detector designed to increase the sensitivity of present interferometers by approximately one order of magnitude. Two reference designs are currently under investigation: a triangular-shaped detector with 10 km arms, and a configuration with two L-shaped detectors with 15 km arms, both located in Europe. Each arm will host a 'xylophone' setup of two interferometers: one optimized for high frequencies, the other, cryogenic, for low frequencies. This design will significantly expand the observable volume of the Universe and improve source parameter estimation. In this contribution, I will outline the scientific program of the ET, tracing the project's evolution, current status, and prospects. We give an overview of the technological challenges, especially for the low-frequency instrument, and the scientific reach of a third-generation detector like ET, highlighting the potential for discoveries in fundamental physics, multi-messenger astrophysics, and cosmology.
Speaker: Filippo Santoliquido (Gran Sasso Science Institute (GSSI)) -
125
Self-force informed inspiral model for binay black hole mergers
The next generation of gravitational-wave detectors like LISA and the Einstein Telescope will probe new frequency bands and source populations, motivating waveform models for intermediate-mass-ratio inspirals (IMRIs), which are binaries lying between the comparable-mass and extreme-mass-ratio regimes. Beyond their modelling challenge, IMRIs are relevant for multi-messenger astronomy, precision tests of fundamental physics, and studies of black hole formation and dark matter environments.
In this talk I present an approach to modelling non-spinning binary black hole inspirals that combines the results of several frameworks for the relativistic 2-body problem. Since each framework is best suited to a different region of parameter space, the strategy is to build hybrid analytical expressions for the binding energy and gravitational-wave energy flux combining the results of each different formalism. Then, I calibrate the hybrid expressions to Numerical Relativity (NR) data from the SXS catalog. Using the resulting hybrid approach, I implement a new model for the evolution of the gravitational-wave phase into a state-of-the-art phenomenological waveform model, and I validate it by comparing the resulting frequency evolution and waveform mismatches against NR simulations and other current leading models, across comparable and intermediate mass ratios. This approach is promising to bridge comparable and extreme mass ratio regimes and could be useful to study beyond-GR and beyond-vacuum effects.
Speaker: Jesús Yébana Carrilero (University of the Balearic Islands) -
126
From Proto-Neutron Stars to Black Holes: A Multi-Messenger Investigation of Core-Collapse Supernova Dynamics
Abstract Core-Collapse Supernovae (CCSNe) represent an exceptional multi-messenger laboratory: the collapsing stellar core simultaneously generates gravitational waves (GWs) and a neutrino burst encoding the physics of compact object formation, yet remains opaque to electromagnetic observations. The original contribution of this work is the exponential modelling of the time-frequency evolution of the High-Frequency Feature (HFF), the dominant GW spectral component produced by pressure-mode oscillations of the nascent Proto-Neutron Star (PNS) surface, isolated in the second Intrinsic Mode Function via the Hilbert-Huang Transform (HHT). This exponential decay has a direct physical foundation: progressive PNS radius decrease and thermal cooling drive a monotonic increase in the characteristic oscillation frequency during a post-bounce temporal window. Furthermore, the parameters of this physically motivated fit provide direct insights into the properties of the PNS and its progenitor. Crucially, we demonstrate that the asymptotic frequency, evolutionary amplitude, and relaxation timescale all exhibit a direct, monotonic dependence on the PNS mass. The HHT, chosen over fixed-basis wavelet methods for its adaptive handling of non-linear, non-stationary GW emission, effectively isolates the matter memory signature, the Standing Accretion Shock Instability, and the HFF across all channels. Applied to 16 three-dimensional CCSN simulations spanning 9.5–60 𝑀⊙ encompassing canonical neutrino-driven explosions, energetic explosions, modest supernovae leaving a black hole (BH) remnant, and “silent” collapses forming BHs directly, the model extracts PNS decay timescales 𝜏GW with a mean relative uncertainty of ∼ 3.4%. Cross-validation with the neutrino messenger reveals a non-trivial correlation: the extracted GW timescales match the neutrino luminosity collapse scales within a mean statistical tension of just ∼ 1.4 𝜎. A dedicated window-optimisation study identifies a 25% amplitude threshold as the optimal fitting range, yielding stable asymptotic frequency ( 𝑓max) estimates without multi-messenger priors. Notably, a Welch coherence analysis reveals a multi-messenger correlation in failed supernovae amid extreme dynamics in the final seconds preceding BH formation. Consistently across all analysed directions, a coherence peak of ∼ 0.75 emerges at the predicted secular shock front oscillation frequency, linking the HHT amplitude with the neutrino signal, resolving theoretically anticipated features elusive in standard analyses. Ultimately, identifying these cross-correlated signatures provides a physical framework to optimise matched filtering algorithms, establishing a multi-messenger baseline for signal extraction in LIGO-Virgo-KAGRA networks and the Einstein Telescope.
Speaker: Giuseppe Aurelio Miserendino -
127
Probing Modified Gravity with Gravitational Wave Strong Lensing
In the next decade, third-generation gravitational wave detectors will become operational, providing us with millions of new signals per year. Just like light, gravitational waves can be bent by the gravitational field of matter and experience the phenomenon of gravitational lensing. We expect that, over a 10-year period, tens of thousands of signals will be strongly lensed. Strongly lensed gravitational wave signals are observed as repeated images of the same event, arriving with a measurable time delay between them. Recent studies (e.g., Jana et al. 2024) have shown that both the time delay distribution and the number of strongly lensed events can be used to constrain cosmological parameters.
Building on this idea, we study how the same observables can also be used to constrain alternative theories of gravity and test general relativity. We focus on how modifications to gravity affect the distribution of dark matter, therefore impacting the lens population. This is described by the halo mass function, which gives the number of dark matter halos per unit volume and unit mass. In particular, Gupta et al. (2022) showed that modified gravity theories affect the halo mass function through a modification of the halo multiplicity function, and provided a fitting formula based on N-body simulations for a range of gravity models.
As a case study, we examine the Hu-Sawicki f(R) model, using different values of the model parameter to represent different deviations from general relativity. We implement these modifications in HMFcalc, a public tool for computing halo mass functions, and use the results to calculate the expected time delay distributions and the number of lensed events under different gravity models.
Our results show that the gravity models can be distinguished based on these observables, and that we can infer the true model of gravity from a set of different gravity models by performing Bayesian model selection.Speaker: Izumi Takimoto Schmiegelow (Gran Sasso Science Institute)
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124
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Direct Dark Matter detection: 2 Aula C
Aula C
Chemistry Department, University Sapienza
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128
An idea for an ultra-broadband axion experiment
I will discuss a novel broadband strategy to search for axions by leveraging observables controlled by the axion field squared. A practical implementation of this concept, allowing to probe the axion–photon coupling, is to operate a dc SQUID at the flux sweet spot. There, the output voltage depends quadratically on the magnetic flux. Using lock-in modulation one can also evade low-frequency noise.
The proposed setup is ultra-broadband, spanning over 15 orders of magnitude in axion mass, with further expansion of the mass range possible. The projected sensitivity is |gaγγ| ≳ 10^{-16} GeV^{-1}, orders of magnitude better than current bounds, and largely independent of axion mass. I will discuss the sources of systematic background and a nulling technique to reduce them to an acceptable level.
This strategy can be extended to other axion couplings and other wave dark matter candidates.
Based on a work in collaboration with Kin Chun Fong and Lam Hui (2605.11078).Speaker: Angelo Esposito (Istituto Nazionale di Fisica Nucleare) -
129
First Search for Solar Axions with the CUPID-0 Scintillating Bolometric Detector
CUPID (CUORE Upgrade with Particle IDentification) is a next-generation cryogenic experiment designed to investigate the Majorana nature of neutrinos through the search for neutrinoless double-beta decay. Its scintillating bolometers, operated at temperatures of approximately 10 mK underground at Laboratori Nazionali del Gran Sasso, provide excellent energy resolution, particle identification, and ultra-low background levels. These features also make the CUPID technology well suited for searches for rare phenomena beyond the Standard Model.
This contribution presents the first ever search for solar axions performed with CUPID-0, the first demonstrator of the CUPID technology, based on an array of scintillating ZnSe crystals enriched in $^{82}$Se. The analysis investigates three possible axion interaction channels in the detector crystals by searching for their expected signatures in the measured energy spectrum. A spectral fit incorporating a detailed model of the observed background components was used to constrain a possible axion contribution.
As no evidence for a signal was found, an upper limit was set on the number of axion-induced events and on the corresponding axion coupling constants. This result demonstrates the sensitivity of scintillating cryogenic calorimeters to axion searches and establishes a methodological basis for future studies with the full-scale CUPID experiment, which will benefit from larger exposure and lower background levels.
Speaker: Livia Petrillo (Istituto Nazionale di Fisica Nucleare) -
130
Constraining the effective axial-vector coupling through precision β spectroscopy: the GAIAS experiment
The determination of the effective axial-vector coupling constant g$_A$ in nuclear media is a major open problem in contemporary neutrino and nuclear physics. Its deviation from the free-nucleon value directly affects the interpretation of neutrinoless double beta decay ($0\nu\beta\beta$) searches through the associated nuclear matrix elements, and therefore impacts the extraction of constraints on the Majorana neutrino mass scale and other parameters in models that allow for lepton number violation.
The GAIAS (GAxIal Analysis with Scintillators) experiment addresses this problem through high-precision beta spectroscopy of forbidden non-unique beta decays using high optical quality and low-background crystal scintillators. For these transitions, the beta spectral shape exhibits a strong sensitivity to g$_A$, particularly in the low-energy region, providing a powerful tool for developing nuclear models that describe weak interactions in nuclei.
The experiment is being installed at the underground Gran Sasso National Laboratory (LNGS) of INFN, where the ultra-low-background environment enables high-statistics measurements under highly stable conditions, with a high signal-to-background ratio. Particular attention will be devoted to crystal growth and a beta-active nuclide of interest incorportation techniques. GAIAS aims to provide very precise beta spectrum measurement, improving constraints on the effective axial coupling constant and to strengthen the role of functional crystalline materials in frontier research at the interface of nuclear, particle, and astroparticle physics.Speaker: Alice Leoncini (Istituto Nazionale di Fisica Nucleare) -
131
From CUORE to CUPID: Toward a Next Generation Search for Neutrinoless Double Beta Decay.
The search for neutrinoless double beta decay (0νββ) is fundamental for investigating lepton-number violation, probing new physics beyond the Standard Model, and determining whether neutrinos are Majorana particles. CUORE, a cryogenic calorimetric experiment at LNGS, studies 0νββ in 130Te using 988 TeO₂ crystals, reaching a tonne-scale mass and operating below 15 mK. Since 2017, CUORE has accumulated close to 3.0 tonne-years of exposure, constraining 0νββ in 130Te and achieving one of the most precise two-neutrino double beta decay (2νββ) half-life measurements and a detailed background reconstruction across a broad energy range. The next generation of experiments aims to probe half-lives greater than 10^27 years, reaching the sensitivity required to explore the Inverted-Ordering region of the neutrino mass spectrum. CUPID (CUORE Upgrade with Particle IDentification) will search for the 0νββ decay of 100Mo, leveraging the existing cryogenic infrastructure and expertise gained from CUORE. CUPID will utilize scintillating Li₂MoO₄ crystals enriched in 100Mo, coupled with light detectors featuring Neganov-Trofimov-Luke amplification. With a total isotope mass of 240 kg, CUPID is designed to achieve a background index of 10⁻⁴ counts/keV/kg/year and a FWHM energy resolution of 5 keV. This performance will allow for a 3σ discovery sensitivity of 1.0 × 10ˆ27 years after 10 years of life-time, corresponding to an effective Majorana neutrino mass sensitivity in the range of 12–21 meV. This work presents the latest CUORE results, recent findings from the CUPID demonstrator, and outlines the forthcoming milestones toward the realization of the CUPID experiment.
Speaker: Stefano Di Lorenzo (Istituto Nazionale di Fisica Nucleare) -
132
Search for Sterile Neutrinos with CUPID-0
CUPID-0 was a pilot experiment based on ZnSe scintillating cryogenic calorimeters, originally designed to search for neutrinoless double beta decay of $^{82}$Se. By simultaneously measuring heat and scintillation light, CUPID-0 achieved efficient particle identification and a powerful rejection of surface $\alpha$ backgrounds, reaching background levels of $\mathcal{O}(10^{-3})$ counts/keV/kg/year in the neutrinoless double beta decay region of interest.
Beyond its primary goal, the performance of CUPID-0 enabled an accurate characterization of the Standard Model two-neutrino double beta decay spectrum and of the residual radioactive background, making it possible to investigate subdominant processes through precision spectral-shape studies.
In this contribution, we present a search for sterile neutrinos in the MeV mass range through an exotic double beta decay mode of $^{82}$Se. Sterile neutrinos are hypothetical particles that may play a role in the origin of neutrino masses and, in some scenarios, be connected to the dark matter problem. The results provide complementary laboratory constraints on sterile neutrinos through nuclear-decay kinematics and highlight the potential of scintillating cryogenic calorimeters for precision searches for physics beyond the Standard Model.
Speaker: Sylvie Pietrarota (Istituto Nazionale di Fisica Nucleare)
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128
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Poster session: poster esposition and presentation
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133
DarkSide Proto-0: The Dual-Phase Argon TPC Prototype for DarkSide-20k
DarkSide-20k is a next-generation experiment for the direct detection of WIMP dark matter, based on a 20-ton fiducial dual-phase liquid argon Time Projection Chamber (TPC) under construction at LNGS. To validate several of the novel technologies adopted for the final detector and optimize its operation, the DarkSide Proto-0 detector has been developed as a compact dual-phase argon TPC, the first fully functional dual-phase TPC implementing key detector solutions developed for DS20k. These include transparent conductive coatings for field shaping, gas pocket formation and, in particular, the Photon Detection Units (PDUs), large-area silicon-based photosensors produced and characterized by the DarkSide collaboration for the optical readout of DarkSide-20k. Proto-0 features a flexible geometry, with independently movable detector elements, allowing an adjustable liquid–gas interface position and gas pocket thickness. This configurable geometry enables dedicated studies of charge extraction and electroluminescence signal (S2) formation under different operating conditions.
A new cryogenic data-taking campaign is currently underway with the goal of further characterizing detector performance and optimizing the operational parameters relevant for DarkSide-20k. This contribution will present the status of the detector and the first results from this campaign, with particular focus on S2 signal formation, detector stability, and on the performance of DarkSide-20k custom photosensors in dual-phase argon operation.Speaker: Camilla Salerno (Istituto Nazionale di Fisica Nucleare) -
134
Production of Radiopure Argon for the DarkSide-20k Dark Matter Experiment: The Aria and Urania Projects
Liquid argon is an excellent target for direct dark matter detection thanks to its scintillation and ionization responses combined with strong pulse-shape discrimination (PSD). The DarkSide-20k experiment, now under construction in the Gran Sasso National Laboratory (LNGS), Italy, will use a liquid argon dual-phase time projection chamber aiming at a background-free search for Weakly Interactive Massive Particles (WIMP). The use of argon sourced from the atmosphere would limit the size of such a detector by the presence of 39Ar, a 𝞫-emitter of cosmogenic origin whose activity poses significant background and pile-up concerns for a multi-tonne scale detectors. To mitigate this background the Global Argon Dark Matter Collaboration (GADMC) has developed a dedicated supply chain for the production of radiopure argon extracted from the underground, hence naturally shielded from cosmic rays and highly depleted in 39Ar.
The first phase of this program is the Urania extraction facility located in Colorado, USA. Urania is designed to obtain the underground argon (UAr) from the active gas wells. The plant is scaled to extract 121 tonnes of UAr at a purity of 99.99%, providing the raw target mass required for the forthcoming DarkSide-20k detector. To achieve ultimate detector-grade quality, the UAr is then transported to the Aria facility located in a mine shaft in Sardinia, Italy. Aria hosts a 350 meter tall cryogenic distillation column. It is designed to chemically purify the UAr to a purity exceeding 99.9999%. Together, Urania and Aria, represent a pioneering industrial scale effort in radiopure material production enabling the next generation rare-event detection technology. Additionally Aria can act as an active isotopic separation plant and has demonstrated the separation of stable argon isotopes (36Ar, 38Ar, and 40Ar). This unlocks broader enrichment opportunities for rare-event searches (using 136Xe, 76Ge) and medical diagnostics (with 18O).
Speaker: Celin Rachel Hidalgo Ochoa (Istituto Nazionale di Fisica Nucleare) -
135
Adiabatic response in the Migdal Effect
The Migdal effect---the prompt ionization induced by a sudden nuclear recoil---is widely used in direct dark matter searches, yet its validity beyond the impulse approximation has remained unresolved. In this talk, I will present the first ab initio calculation for isolated atoms that goes beyond the impulse approximation, establishing the adiabatic crossover where ionization is suppressed. I will show that this behavior is fully encoded in the scattering amplitude, without ad hoc assumptions, and map the relevant parameter space, finding that dark matter searches lie in the unsuppressed regime. I will further show interesting connections of this work in the calibration of the Migdal effect through neutrons and in semiconductor systems.
Speaker: Mukul Sholapurkar (MBI, Vienna) -
136
Projected duty cycle and seismic site characterisation for the Einstein Telescope
The selection of the host site for the Einstein Telescope (ET), the European future third-generation gravitational-wave observatory, demands a rigorous assessment of the local seismic environment. This study presents a systematic evaluation of both natural and anthropogenic noise sources at candidate locations. By analyzing the Root-Mean-Square (RMS) seismic amplitude over the critical low frequency bands, we track short-term non-stationarities and temporal noise fluctuations. Long duration time intervals of low ambient noise are identified and translated into projected detector sensitivity limits. This approach allows us to model and predict the operational duty cycle of the future interferometer, providing a robust, predictive framework to compare the scientific yield of candidate sites.
Speaker: Davide Rozza (University of Milano-Bicocca and INFN-MIB) -
137
The Spectator Field Nexus: Connecting Primordial Black Holes, Gravitational Waves and Baryogenesis
Primordial Black Holes (PBHs) have emerged as a compelling candidate for dark matter and a possible explanation for baryon asymmetry, while also offering testable links to gravitational wave (GW) observations. However, their formation within single-field inflationary models requires a finely tuned, short-lived ultra-slow-roll (USR) phase, which undermines theoretical naturalness and predictive stability. In this work, we propose a spectator-assisted inflationary framework (PBHspec) that introduces a subdominant scalar spectator field alongside the inflaton. The spectator field modifies the Hubble friction, enabling a prolonged slow-roll regime that mimics USR without extreme parameter tuning. This mechanism naturally amplifies curvature perturbations, broadening the parameter space for PBH formation and simultaneously enhancing scalar-induced gravitational waves (SIGWs). Furthermore, by incorporating bilinear quadratic couplings between the inflaton and spectator field, and Yukawa-type couplings between the spectator and gravity, the framework provides a robust mechanism for baryogenesis, raising the baryon asymmetry parameter to observed values. Numerical simulations confirm that PBH abundance, GW spectra, and baryogenesis can be consistently achieved within this unified setup. The PBHspec model thus establishes a nexus between PBH formation, gravitational wave production, and baryogenesis, offering a theoretically appealing and observationally testable extension of inflationary cosmology.
Speaker: Bharti Kaushik -
138
Search for Non-Relativistic Magnetic Monopoles with the IceCube Neutrino Observatory
Magnetic monopoles are beyond standard model particles with a discrete magnetic charge. They are predicted by Grand-Unified-Theories to be created during the early Universe, and, with masses on the GUT-scale, moving at non-relativistic speeds. IceCube published its first analysis on magnetic monopoles in this phase space in 2014, using 1 year of livetime, and still sets the strongest limit on them today. Since then, we have not only increased the available livetime by a factor of ten but also improved our analysis methods, utilising modern machine learning techniques, and the modelling of the physics of magnetic monopoles, including not only the light emission due to nucleon decays induced via the Rubakov-Callan effect, but also the luminescence light emitted from the interaction of the monopole with the surrounding ice. Combining this, we are able to perform a background-free analysis, improving our sensitivity by a factor of up to 100 compared to the previous limits, depending on the specific monopole phase space. In this talk, we present the latest results from this search for non-relativistic magnetic monopoles.
Speaker: Jonas Häußler -
139
Search for fractionally charged particles with the IceCube neutrino observatory
Free particles with a charge smaller than the elementary charge (fractionally charged particles) are predicted by numerous Beyond the Standard Model theories of physics, in particular by supersymmetric theories. This presentation presents a search for a naturally occurring flux of particles with charge between 1/3 e and 2/3 e with 12 years of data from the IceCube neutrino observatory in its full detector configuration. For an isotropic flux of fractionally charged particles in the vicinity of the detector, we observe a slight excess over the background expectation, and set world-leading limits of the order of 10⁻¹⁵ cm⁻² s⁻¹ sr⁻¹. In addition, limits are also determined for a flux of fractionally charged particles which is isotropic at the surface, taking into account the absorption due to traversing the overburden of ice above IceCube.
Speaker: Alexander Sandrock (University of Wuppertal) -
140
Rare alpha decays of natural Hf isotopes with low-background Cs₂HfCl₆ crystal scintillators
Low-background crystal scintillators are widely employed in underground searches for rare events, where particle identification and control of intrinsic radioactive contaminants are essential. We report new measurements of rare $\alpha$ decays of naturally occurring Hf isotopes performed with four Cs$_2$HfCl$_6$ crystal scintillators operated in the DAMA/CRYS low-background setup at the Gran Sasso National Laboratory of INFN. The "source = detector" approach provides high sensitivity to ultra-long-lived processes by embedding the decaying nuclei directly within the detector medium. After a detailed characterization of the detector performance, including assessment of the energy calibration and pulse shape discrimination capability, data collected over 85.23 days have been analyzed. A precise determination of the half-life of the α decay of $^{174}$Hf to the ground state of $^{170}$Yb has been obtained: T$_{1/2}=(2.95\pm0.16)\times10^{16}$ yr, improving the accuracy of previous measurements and confirming their consistency. Particular attention has been devoted to the evaluation of background contributions, especially from the possible $^{147}$Sm contamination, to a proper description of the shape of observed $\alpha$ peaks, and to carefully assess the systematic contributions. No statistically significant signals have been observed for the $\alpha$ decays of other naturally occurring Hf isotopes, i.e. $^{176, 177, 178, 179, 180}$Hf. New lower limits on their half-lives in the range $10^{19}-10^{20}$ yr have been established. These results confirm the potential of Cs$_2$HfCl$_6$ crystal scintillators as a detector medium for rare-event searches and provide relevant input for nuclear structure models of the extremely long-lived $\alpha$ emitters.
Speaker: Alice Leoncini (Istituto Nazionale di Fisica Nucleare) -
141
A compact setup for the PTOLEMY transverse drift filter proof-of-principle
The PTOLEMY project exploits the innovative concept of the transverse drift filter, in which the synergic action of on uniform magnetic field and electric one play a key role. This is used to achieve a controlled reduction of the kinetic energy of electrons within a one-meter transport length. Before implementing this approach in the PTOLEMY demonstrator, a proof-of-principle test will be carried out. To this aim, a cylindrical Halbach permanent magnet — capable of generating a 1 T dipolar magnetic field orthogonal to the cylinder axis inside the hollow — can be employed together with an electron gun as the particle source. The design of the experimental setup and dedicated simulations are presented in this talk.
Speaker: Francesca Maria Pofi (Istituto Nazionale di Fisica Nucleare) -
142
Multi-messenger signatures of magnetar-powered supernovae: UV detection rates and neutron-star ellipticity
A magnetar formed in the core collapse of a massive star is born spinning at millisecond periods, with magnetic fields B ≳ 1014 G and a rotational reservoir that can exceed 1052 erg enough to dominate its host supernova. This energy is shared between two spin-down channels: magnetic-dipole radiation,
which heats the ejecta and powers a bright ultraviolet shock breakout(SBO) followed by a luminous supernova (SN), and gravitational-wave (GW) emission, which operates only if the star carries a non-axisymmetric deformation set by its ellipticity ϵ. Because the two channels draw on the same reservoir, the energy delivered to the ejecta and therefore the brightness of the light curves depends on ϵ. The electromagnetic emission thus becomes an indirect tracer of the deformation that governs the star’s GW output.
Building on the model of Dall’Osso & Guetta (2025), we solve the coupled dipole and GW spin-down together with the thin-shell shock dynamics, radiative diffusion, and the blackbody photosphere to predict the emission that the ULTRASAT satellite (230-290 nm) will detect from these events.
We extend that model in two directions held fixed in earlier work: scanning the full physically motivated ellipticity range (ϵ ∼ 10−5-10−2)and, for the first time in this context, varying the ejecta opacity κ. This yields ULTRASAT detection horizons and annual rates across the magnetar and ejecta parameter space. Mapping the opacity dependence shows that the two channels respond to κ in opposite senses: the SN horizon contracts as opacity rises while the SBO horizon expands an effect invisible to fixed-opacity treatments. Our central aim is to establish which channel is the more sensitive tracer of neutron star ellipticity, and thereby to connect forthcoming wide field UV surveys to the magnetar population as electromagnetic counterparts of long-lived GW transients relevant to LVK and the Einstein Telescope.Speaker: Souvik Mondal (Ariel University) -
143
Simulating Ultra-High-Energy Cosmic Ray anisotropies in the magnetised local Universe
The origin of Ultra-High-Energy Cosmic Rays (UHECRs) remains unknown, despite the recent observation of anisotropies in the UHECR sky above 8 EeV. Identifying their sources requires accounting for the interactions with cosmic photon backgrounds as well as deflections by Galactic and extragalactic magnetic fields (GMF and EGMF). In particular, the strength and structure of the EGMF remain poorly understood. We use the CRPropa 3 Monte Carlo framework to simulate the propagation of UHECRs above 8 EeV in realistic, magnetised replicas of the local Universe. We investigate different source density scenarios and characterise the resulting arrival direction distributions through their angular power spectrum, focusing on the dipole and quadruple moments. We find that the UHECR horizon, already limited by energy losses due to interactions with cosmic photon fields, is further reduced by the magnetic horizon, with the level of suppression depending on the magnetisation of the extragalactic space. Our results show that the observed dipole amplitude can be reproduced, while the predicted quadrupole component is generally larger than observed. We also study the dependence of the angular multipoles on UHECR energy and mass composition.
Speaker: Simone Rossoni (Institut d'Astrophysique de Paris)
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133
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Plenary: 10 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Chair Aldo Morselli
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144
Search for neutrino mass with underground detectors
The absolute neutrino mass scale remains an open question in particle physics and cosmology. While the search for neutrinoless double beta decay primarily tests lepton number conservation, a discovery would provide valuable insight into the origin and scale of the neutrino mass. In this talk, I will review the current status and future prospects of neutrinoless double beta decay experiments and discuss their complementarity with other neutrino mass probes.
Speaker: Christoph Wiesinger -
145
When Neutrinos Scatter Coherently: A New Window on Fundamental Physics
Neutrinos are among the most intriguing particles of the Standard Model (SM). Despite their elusive nature, neutrinos can undergo a process where their interaction cross-section with matter is significantly enhanced: Coherent Elastic Neutrino-Nucleus Scattering (CEνNS). Predicted by Freedman in 1973, CEνNS was first observed in 2017, marking the beginning of a new era in neutrino physics. CEνNS has proven to be a powerful tool for exploring various physics scenarios, motivating a worldwide effort to detect the tiny nuclear recoils produced in this process.
In this presentation, I will review the current status of CEνNS searches, presenting the implications of CEνNS measurements for the SM and beyond. Finally, I will highlight the physics reach of the NUCLEUS experiment, which features cryogenic calorimeters capable of detecting nuclear recoils as low as 20 eV.Speaker: Mattia Atzori Corona (Istituto Nazionale di Fisica Nucleare)
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144
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10:30 AM
Coffee break
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Plenary: 11 Aula Ginestra
Aula Ginestra
Chemistry Department, University Sapienza
Chair Aldo Morselli
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146
PBR (POEMMA Balloon with Radio): Status and Perspectives
The JEM-EUSO Collaboration has been pioneering the development of space-based detectors for the observation of ultra-high-energy cosmic rays and very-high-energy neutrinos through the Earth's atmosphere for nearly two decades. Building on the experience gained with several pathfinder missions, the collaboration is now developing the POEMMA-Balloon with Radio (PBR) mission, a NASA Super Pressure Balloon experiment conceived as a technological and scientific precursor to the proposed Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) satellite mission.
The mission addresses three primary scientific objectives: the first observation of Ultra-High-Energy Cosmic Rays (UHECRs) from above using atmospheric fluorescence, the study of High-Altitude Horizontal Air Showers (HAHAs) through hybrid optical-radio-γ-ray detection, and the search for very-high-energy neutrinos from transient astrophysical sources via Earth-skimming events. Beyond its scientific program, PBR will validate key technologies and observation strategies for future space-based ultra-high-energy particle observatories.
Scheduled for launch from Wanaka, New Zealand, in 2028, PBR will operate at an altitude of approximately 33 km for a mission lasting more than 20 days, providing a unique near-space platform for the observation of ultra-high-energy particles. The payload is hosted on a pointing system capable of orienting the instrument from nadir up to 12° above the horizon, with a 360° azimuthal rotation capability enabling observations of any target direction and the follow-up of transient astrophysical sources through Target of Opportunity (ToO) observations. The payload combines four complementary detection systems: a Fluorescence Camera, a Cherenkov Camera, a Radio Instrument, and an X/γ-ray detector.
The Fluorescence Camera will enable the observation and reconstruction of UHECRs in nadir mode through the detection of UV fluorescence light emitted by extensive air showers developing in the atmosphere. The Cherenkov Camera will allow the search for Earth-skimming tau neutrinos from transient astrophysical sources through ToO observations when pointing below the Earth limb, and the study of HAHAs when pointing above the limb through the detection of Cherenkov emission. In parallel, the Radio Instrument will enable, for the first time, simultaneous optical and radio measurements of HAHAs, while the X/γ-ray detector will provide a unique in-situ probe of the early stages of shower development through the detection of high-energy photons, probing quantities that are not accessible to either ground-based or space-based observatories.
This contribution presents an overview of the PBR mission, its scientific goals, the current status of the payload development, and the expected scientific performance, highlighting its role as a crucial technological and scientific precursor to the POEMMA mission.Speaker: Matteo Battisti (INFN Roma Tor Vergata) -
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JUNO experiment: status report and perspectives
JUNO experiment has been designed primarily to measure the neutrino mass hierarchy exploiting the interference between the oscillations induced by the solar and atmospheric parameters.
It is composed by 20 kton of liquid scintillator and located in the Guangdong region of the Populae Republic of China at 52.5 km distance from two power plants for a total power of 26.6 GWth.
The detector is in data taking fully loaded with the scintillator since the end of August 2025, and released a first measurement of the solar neutrino oscillations parameters, with world leading precision, based on the first 60 days of data.
Recently a new analysis based on more data has been released, improving the previuos measurement and presenting the first encouraging results on neutrino mass hierarchy measurement.Speaker: Alessandro Paoloni (Istituto Nazionale di Fisica Nucleare) -
148
Determination of the energy scale of cosmic ray-measurements using the Auger Engineering Radio Array
Determining the absolute energy scale in cosmic-ray observations is both challenging and of fundamental importance. We show that radio measurements of extensive air showers with the Auger Engineering Radio Array (AERA), combined with per-event CoREAS simulations, enable an accurate calibration of the cosmic-ray energy scale between $3 \times 10^{17}$ eV and several $10^{18}$ eV. To ensure an accurate result, we control individual systematic uncertainties at the 5% level or better. The absolute calibration of the antenna gain and the analog signal chain is performed using the Galactic background emission and detailed antenna gain modeling, cross-checked with laboratory measurements. Further key elements include temperature-dependent amplification corrections, continuous detector monitoring, thunderstorm vetoing, unbiased event reconstruction, and per-event atmospheric modeling. The resulting AERA energy scale is 12% higher than the one established with the Auger Fluorescence Detector, consistent within uncertainties and providing an independent confirmation of the energy scale of the Pierre Auger Observatory.
Speaker: Tim Huege (Karlsruhe Institute of Technology) -
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Concluding RemarksSpeaker: Prof. Antonio Capone (Istituto Nazionale di Fisica Nucleare)
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