NuFact 2026 - The 27th International Workshop on Neutrinos from Accelerators

Aug 31, 2026, 8:00 AM → Sep 5, 2026, 1:00 PM Asia/Shanghai

Tsung-Dao Lee Institute

Kim Siang Khaw (TDLI/SJTU)

NuFact 2026 is the 27th in a series of annual international workshops that began in 1999 as the International Workshop on Neutrino Factories. The name was later changed to the International Workshop on Neutrinos from Accelerators to reflect a broader scope: the program now encompasses all current and future accelerator- and reactor-based neutrino projects, as well as muon physics, far exceeding the original Neutrino Factory concept.

The main goal of the workshop is to review the progress on current and future facilities aimed at improving measurements of neutral- and charged-lepton flavor violation, as well as to search for new phenomena beyond the capabilities of currently planned experiments. The workshop is both interdisciplinary and interregional, bringing together experimenters, theorists, and accelerator physicists from around the world to share expertise and work toward the common goal of assessing the results of ongoing experiments and designing the next generation of experiments. 

The NuFact 2026 workshop is divided into seven working groups to cover the following topics: 

• WG1: Neutrino Oscillations
• WG2: Neutrino Scattering
• WG3: Accelerator Physics
• WG4: Muon Physics
• WG5: Neutrinos beyond PMNS
• WG6: Detectors
• WG7: Inclusion, Diversity, Equity, Education, and Outreach

We invite you to Shanghai to enjoy an exciting week of physics and the chance to experience our amazing city firsthand. See you in August 2026!

NuFact2026_First_Bulletin.pdf

NuFact2026Poster.jpg

Monday, August 31

Registration

Welcome

1 Open Remarks

Speaker: Prof. Kim Siang Khaw (TDLI/SJTU)

Plenary: Work Package Introductions (WG1-WG5)

2 WG1 - Neutrino Oscillations

3 WG2 - Neutrino Interactions

4 WG3 - Accelerators

5 WG4 - Muon Physics

6 WG5 - Neutrinos Beyond PMNS

10:30 AM Coffee Break

Plenary: Working Package Introductions (WG6-WG7)

7 WG6 : Detectors

8 WG7 : Inclusion, Diversity, Equity, Education and Outreach

Plenary: Plenary (Monday AM)

9 Latest T2K Results

T2K is a long-baseline neutrino experiment operating in Japan which has achieved world-leading measurements of neutrino and anti-neutrino oscillation. The J-PARC accelerator complex produces a stream of muon neutrinos or anti-neutrinos which are measured at a near detector complex as well as at a Water Cherenkov far detector, Super-Kamiokande, 295km away. Near and far detector measurements of the rates of electron neutrino appearance for neutrinos and anti-neutrinos can be used to quantify the degree of the charge-parity violating phase $\delta _{CP}$. A new analysis with improvements such as upgraded selection and detector modelling at the near detector, as well as new Gd-loaded far detector data with improved phase space coverage due to novel samples with charged pions, extension of the neutrino interaction model and enhanced interaction systematics treatment will be presented in this talk. In addition, results from the neutrino cross-section program as well as future prospects of T2K will be discussed.

Speaker: Felix Cormier (TRIUMF)

10 Recent Oscillation Analysis and Results from NOvA

NOvA is a long-baseline, accelerator-based neutrino oscillation experiment, optimized for electron neutrino measurements. It utilizes the upgraded, Megawatt-capable NuMI beam from Fermilab to measure electron-neutrino appearance and muon-neutrino disappearance at its Far Detector in Ash River, Minnesota. NOvA's goals include resolving the neutrino mass hierarchy problem, constraining the CP-violating phase, and determining the octant of theta23.

This talk will present NOvA's latest oscillation analyses and results based on the full ten-year dataset collected between 2013 and 2023, including both combined and independent fits to muon-(anti)neutrino disappearance and electron-(anti)neutrino appearance data. Combined with constraints from reactor neutrino experiments, the new results further strengthen the preference for the normal mass ordering.

Speaker: Jianming Bian (University of California, Irvine)

12:30 PM Lunch

Plenary: Plenary (Monday PM-1)

11 Recent Neutrino Oscillations Results from JUNO

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment located in southern China. It features a \SI{20}{kton} liquid scintillator detector designed primarily to measure antineutrinos emitted from the Taishan and Yangjiang nuclear power plants, both situated at a baseline of 52.5 km. Its core physics goals include determining the neutrino mass ordering and performing high-precision measurements of oscillation parameters. JUNO began data taking in late August 2025 and released its first physics results in November 2025. This talk presents the recent results on the neutrino mass ordering, along with precision precision measurements of Δm²₃₁, Δm²₂₁, and sin² 2θ₁₂.

Speaker: 黄俊挺 （Junting Huang） (Shanghai Jiao Tong University)

12 New Results from Super-Kamiokande

Super-Kamiokande is a large water Cherenkov detector located in Mount Ikenoyama, Japan, which recently celebrated its 30th anniversary of operation. We present several new results, including new atmospheric, supernova, and solar analyses. The new atmospheric oscillation analysis includes the period SK VI, the first period where gadolinium was introduced into the water for enhanced neutron capture efficiency. Neutron information is used both for separation of neutrinos and antineutrinos, as well as for a correction to estimates of direction and energy. In addition, a new search for diffuse supernova neutrino background (DSNB) will be presented, also including gadolinium loaded periods.

Speaker: Ben Jargowsky (Boston University)

13 Towards high-resolution 3D tracking in scintillator-based neutrino detectors

Scintillator-based detectors are widely used in neutrino experiments owing to their particle-tracking and calorimetry capabilities.
Traditionally, achieving high spatial resolution alongside a massive active target requires both segmentation and optical separation, that comes at the cost of increased manufacturing complexity and a massive number of readout channels.
To overcome these challenges, newly developed technologies aim to enhance 3D tracking performance in future neutrino experiments without sacrificing target mass. For plastic scintillators, current efforts include the high-precision assembly of tiny scintillating cubes or fibers, as well as 3D-printing optically-isolated voxels within monolithic blocks. Similarly, 3D optical separation or tracking in opaque liquid scintillators present promising options.
Finally, recent developments showed sub-millimeter tracking resolution in unsegmented scintillators using arrays of light-field cameras.
After a brief review of scintillator detectors deployed in current experiments, I will discuss ongoing R\&D geared toward future facilities.

Speaker: Prof. Davide Sgalaberna (ETH Zurich)

3:30 PM Coffee Break

Plenary: Plenary (Monday PM-2)

14 Lepton EDM Physics Overview

Lepton EDM Physics Overview

Speaker: Prof. Maxim Pospelov (University of Minnesota)

15 The search for the muon electric dipole moment at Fermilab Muon g-2

After 6 years of taking data, the Muon g-2 Experiment measured the anomalous magnetic moment of the muon to a final precision of 127 ppb. In parallel to this analysis, it is possible to perform a measurement of the muon electric dipole moment (EDM) using the straw tracker detectors. In the Standard Model (SM) EDMs are predicted to be vanishingly small. A non-zero muon EDM would constitute physics beyond the SM and be a source of charge-parity violation. The current limit on the muon EDM was set by the predecessor experiment at Brookhaven National Laboratory, giving $|d_{\mu}|<1.8\times10^{-19} e\cdot$cm at a 95% confidence level - Fermilab will improve on this limit. This talk will present the methodology and latest results of this measurement.

Speaker: Lucy Bailey (UCL)

16 SBND Detector Status and First Results

The Short-Baseline Near Detector (SBND) is one of three liquid argon time projection chamber (LArTPC) neutrino detectors positioned along the axis of the Booster Neutrino Beam (BNB) at Fermilab, and serves as the near detector in the Short-Baseline Neutrino (SBN) Program. The detector just completed its second year of running, collecting over 6.5e20 POT, equivalent to an unprecedented sample of over 5 million neutrino interactions. Initial data has demonstrated superb performance of the detector’s subsystems, enabling precise tracking and calorimetric reconstruction of events. With this large statistical data set, SBND is performing multi-dimensional cross section measurements of inclusive and exclusive topologies and precise searches for beyond the Standard Model (BSM) processes. As the near detector in the SBN Program, it will enable the full potential of the joint sterile neutrino measurements program by precisely characterizing the unoscillated neutrino beam, constraining BNB flux and neutrino-argon cross-section systematic uncertainties.
In this talk, the current status of the experiment, first results from SBND’s neutrino interaction program, as well as status and prospects for BSM and oscillation searches are discussed.

Speaker: Thomas Benjamin Wester (University of Chicago)

Poster

17 Atmospheric Neutrino Selection and Reconstruction in JUNO

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment located in southern China, featuring a 20-kton liquid scintillator detector with excellent energy resolution and large target mass. JUNO has been collecting full liquid scintillator data since August 2025. While primarily designed to determine the neutrino mass ordering (NMO) using reactor antineutrinos, JUNO offers unique potential for atmospheric neutrino measurements, which can provide independent and complementary sensitivity to the NMO. This poster presents the latest progress towards the first atmospheric neutrino measurement at JUNO. Latest status on fully contained event selection, background rejection, and reconstruction performance are reported.

Speakers: Mr 王家斌 （Jiabin Wang） (Shandong University), 谭晓晗 （Xiaohan Tan） (Shandong University)

18 Calorimeter-Based EDM Analysis for the Fermilab Muon g−2 Experiment

The muon electric dipole moment (EDM) is a sensitive probe of charge-parity (CP) violation and physics beyond the Standard Model. In the Fermilab Muon g−2 experiment, an EDM introduces an additional spin-precession component that produces a vertical oscillation in the decay-positron distribution that can be measured by the calorimeters. For a muon EDM smaller than the current limit set by the BNL Muon g-2 collaboration, this oscillation occurs at the anomalous precession frequency ($\omega_a$). It's 90° out of phase with the horizontal oscillation induced by the muon magnetic dipole moment (MDM), providing a distinct signature for an EDM search. We present a preliminary calorimeter-based EDM analysis using the Fermilab Muon g−2 dataset. Geant4 simulations with a range of muon EDM values are used to extract the conversion factor that relates the amplitude of the EDM-induced vertical-position oscillation to the muon EDM magnitude. The same simulation approach is used to study systematic effects that could mimic EDM signals, including beam dynamics and detector-related effects. Preliminary results from these studies are presented, showing the impact of potential systematic contributions on EDM extraction. By combining the simulated EDM conversion factor with the expected statistical precision, we evaluate the projected sensitivity to the muon EDM and discuss prospects for improving constraints on CP-violating physics beyond the Standard Model.

Speaker: Mr 曾永浩 (Yonghao Zeng) (Tsung-Dao Lee Institute, Shanghai Jiao Tong University)

19 Cosmic Muon Track Reconstruction in JUNO

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20-kton liquid scintillator detector designed for the determination of neutrino mass ordering and precise neutrino oscillation parameter measurements. Accurate reconstruction of cosmic muon tracks is essential for suppressing cosmogenic backgrounds and improving the neutrino signal efficiency.
In this poster, we present a comprehensive overview of the muon reconstruction algorithms developed for JUNO. Preliminary reconstruction performance and muon angular spectrum measurements are reported. This work demonstrates that JUNO can achieve precise cosmic muon track reconstruction, enabling more efficient cosmogenic background suppression while preserving detector live time.

Speakers: 朱峻毅 （Junyi Zhu） (Shandong University), 魏俊雅 （Junya Wei） (Shandong University)

20 Data-driven Charge Template Reconstruction for the TAO Liquid Scintillator Detector

The Taishan Antineutrino Observatory (TAO) is a compact spherical liquid scintillator detector designed to achieve excellent energy resolution for precision reactor antineutrino measurements. Owing to the compact detector geometry, photon timing information provides limited discrimination for event reconstruction, motivating the development of a reconstruction algorithm based solely on the SiPM charge response.

We present a data-driven Charge Template reconstruction method that simultaneously reconstructs the event vertex and visible energy using a maximum-likelihood approach. Calibration data collected with deployed Ge-68 and Cs-137 radioactive sources are used to construct a three-dimensional detector response map describing the expected photoelectron yield as a function of event position and the relative SiPM geometry. The excellent single-photoelectron resolution of the TAO SiPM system enables reliable photoelectron counting, allowing the detector response to be modeled directly in photoelectron space while suppressing the impact of correlated electronic noise. During reconstruction, the measured SiPM charge pattern is compared with the expected response predicted by the 3D nPE map, and the event parameters are obtained through likelihood minimization. Since the detector response model is derived directly from calibration data, detector non-uniformities are naturally incorporated into the reconstruction without requiring additional position-dependent energy corrections.

The proposed method establishes a fully calibration-driven reconstruction framework for TAO and provides a robust approach for precision energy and vertex reconstruction in compact liquid scintillator detectors.

Speaker: 皮旻 （Min Pi) (武汉大学)

21 Detector R&D of a Cold Liquid Scintillator Veto for the PandaX-20T Experiment

The PandaX-20T experiment, a next-generation multi-ton liquid xenon TPC at the China Jinping Underground Laboratory, aims to achieve unprecedented sensitivity for direct dark matter detection. As experiments approach the neutrino-floor regime, efficient suppression of neutron and gamma-induced backgrounds becomes increasingly important. An active Cold Liquid Scintillator (CLS) veto surrounding the xenon target offers a promising approach for enhancing background discrimination, with the additional benefit of reducing thermal gradients and potentially enabling a thinner liquid-xenon cryostat.

We report R&D results from a ~1 L CLS prototype operated down to −100°C,
employing wavelength-shifting optical fibers coupled to silicon photomultipliers (SiPMs) for scintillation readout under cryogenic conditions. The system demonstrates stable operation, with a ~59% reduction in photoelectron yield at −20 °C relative to room temperature. Independent LED calibration measurements confirm reliable SiPM performance at −100 °C, with an observed gain increase of about a factor of two. Geant4 simulations are employed to model optical photon transport, optimize detector geometry, and evaluate neutron and gamma veto performance. These combined studies provide essential input for the design of a large-scale cryogenic scintillator veto for PandaX-20T and demonstrate its potential to significantly enhance background rejection in rare-event searches. Future work will focus on detailed characterization at −100 °C and quantification of neutron-tagging efficiency.

Speaker: Roni Dey (TDLI,SJTU)

22 Development of a new SiPM-based Beam Loss Monitor for the J-PARC Neutrino Beamline

A new Beam Loss Monitor (BLM) is being developed for the J-PARC neutrino beamline. Several detectors will be installed in and immediately downstream of the Main Ring (MR) fast-extraction region, where the 30 GeV proton beam is extracted toward the neutrino production target. Designed for operation in a high-radiation environment and to remain compatible with the planned J-PARC neutrino beamline upgrades for the Hyper-Kamiokande era, including proton beam powers up to 1.3 MW, the BLM will provide bunch-by-bunch beam loss measurements. The detector is based on a new type of Silicon PhotoMultipliers (SiPMs) with higher resistance to radiation than normal, coupled to a radiation-hard active material. Candidate materials currently under evaluation include scintillators, scintillating fibers, and fused silica. The beam-loss signals will be used to assess the beam characteristics at the fast-extraction region - and in particular to infer the beam halo transported from the Main Ring - and to provide information relevant to beam-induced material activation for radiation safety. The new monitors are under development and will be tested during the upcoming T2K beam operation.

Speaker: Camilla Forza

23 Elastic neutrino-electron scattering perspectives at nuclear reactors

The determination of the weak mixing angle, $\sin^2\theta_W$, at low momentum transfers remains a powerful test of the Standard Model and its potential new physics extensions. Here, I will explore some physics opportunities at present and future reactor neutrino experiments through elastic neutrino-electron scattering (E$\nu$ES). I will show the expected sensitivity to the weak mixing angle considering the CLOUD, TAO, and DANSS experimental configurations. Additionally, I will present the projected upper limits for the non-standard neutrino interactions (NSI), effective neutrino magnetic moment ($\mu_\nu$) and the neutrino transition magnetic moments ($\Lambda_i$). These results demonstrate the physics potential of the E$\nu$ES channel at current and upcoming reactor-based neutrino experiments.

Speaker: Luis A. Delgadillo (IHEP)

24 End-to-End, Machine-Learning-Based Michel Electron Reconstruction in ICARUS

The ICARUS detector, a LArTPC (Liquid Argon Time Projection Chamber) of 476 tons fiducial volume, serves as the Far Detector of the SBN (Short Baseline Neutrino) program. ICARUS is situated on-axis with respect to the BNB and off-axis to the NuMI neutrino beams at Fermilab. LArTPC is a powerful detector technology for achieving precise neutrino interaction imaging and reconstruction in 3D, thanks to its mm-scale spatial resolution. An end-to-end, scalable reconstruction chain referred to as "SPINE" (Scalable Particle Imaging with Neural Embeddings) makes use of Sparse Convolutional Neural Networks for voxel-level information extraction and Graph Neural Networks for particle-level structure clustering in a hierarchical framework to analyze data. This talk presents the reconstruction performance of SPINE on Michel electrons in ICARUS. Michel electrons, the daughter particles of muons decaying at rest, have well-defined energy spectra, making them ideal targets for detector energy scale calibration below 100 MeV. Understanding Michel electrons in ICARUS is key to the successful application of machine learning techniques toward SBN neutrino oscillation physics.

Speaker: Junjie Xia (SLAC/Stanford University)

25 Energy Response Model of the JUNO Central Detector

Energy Response Model of the JUNO Central Detector

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator detector that started data-taking since late Aug,2025. The primary physics goal is to determine the neutrino mass ordering through a precision measurement of the reactor anti-neutrino energy spectrum. This requires a precise calibration of energy nonlinearity and resolution of positrons in the JUNO detector, which are produced in the reactor anti-neutrino inverse beta decay (IBD) interactions.

This poster presents a model called COMbined model of Energy and Energy Resolution (COMEER), which models detector response of JUNO based on Geant4 step simulations. The model is constrained by data of radioactive gamma sources with various energies deployed at different positions to make precise predictions for the nonlinearity and resolutions of positrons in JUNO.

By correlating energy non-linearity and resolution in Geant4 step-level information with only 3 parameters, COMEER achieves precise prediction simultaneously for non-linearity and resolution of the uniformly distributed IBD positrons, providing a key input to the reactor anti-neutrino oscillation analysis.

Speaker: 廖依林 (Yilin Liao)

26 Implementation of QED radiative corrections theory for photon emission prediction in the NEUT event generator

The accelerator-based neutrino oscillation experiment T2K aims to investigate neutrino CP violation by measuring differences in oscillation probabilities between neutrinos and antineutrinos. One of the dominant sources of systematic uncertainty in T2K arises from neutrino–nucleus interaction modeling. In particular, tree-level photon-emission contributions to the neutrino–nucleus cross section are currently implemented in the event generator NEUT via an empirical model, which may introduce uncertainties in the predicted event rates and thereby affect the precision of oscillation measurements. To estimate these uncertainties, a recently developed theoretical model for radiative corrections to the neutrino–nucleus cross section has been implemented into NEUT. This is the first microscopic theory-based implementation of radiative photon emission in NEUT. Preliminary NEUT predictions based on this implementation will be presented, focusing on radiative photon production in the accelerator-neutrino energy region and its impact on electron- and muon-neutrino interaction predictions. To study the impact of radiative photon production on detector simulation, the energy and angular distributions of radiative photons were generated. Several comparisons between the theoretical predictions and NEUT simulations were also performed to validate the implemented theoretical model.

Speaker: 李赫 (He Li) (Tohoku University)

27 jaxnu-osc: A Fully Differentiable Neutrino Oscillation Engine with Applications in Experimental Sensitivity Optimization

Next-generation neutrino oscillation experiments operate in highly complex parameter spaces where the physics of interest is tightly coupled with multi-dimensional systematic uncertainties. Traditional neutrino oscillation calculators lack gradient information, limiting experimental design, sensitivity forecasting, and profile likelihood fits to computationally expensive, derivative-free grid scans. To address this bottleneck, we present jaxnu-osc, a high-performance, open-source Python package providing a complete, fully differentiable neutrino oscillation engine. The software calculates exact 3-flavor neutrino propagation through continuously varying matter profiles while natively providing exact analytical gradients with respect to all physical, atmospheric, and environmental parameters.

In this work, we demonstrate the unique capabilities of a gradient-aware framework through a primary, physics-driven use case: automated experimental sensitivity optimization. Utilizing a continuous soft-binning architecture, we show how jaxnu-osc calculates exact sensitivity gradients to dynamically warp and optimize 2D analysis bin boundaries (Energy vs. Zenith Angle), mathematically maximizing an experiment's statistical sensitivity to neutrino oscillations. Additionally, we showcase how this differentiable pipeline seamlessly accelerates high-dimensional parameter profiling, such as simultaneous fits of complex Non-Standard Interaction (NSI) matrices or Earth core characteristics. We present the package validation, performance benchmarks, and discuss how jaxnu-osc can be integrated into existing experimental simulation workflows to automate and enhance analysis design.

Speaker: Pierre Granger (CERN)

28 Machine-Learning-Assisted $\nu/\bar{\nu}$ Discrimination in Atmospheric Neutrino Events for CP-Violation Sensitivity in a 20-kton Liquid Scintillator Detector

Although large liquid scintillator detectors are primarily designed for reactor antineutrino measurements, their large fiducial volume and excellent energy resolution also enable the observation of atmospheric neutrino interactions. We investigate the potential of machine-learning-assisted event classification to achieve statistical neutrino–antineutrino discrimination in atmospheric neutrino samples. A classifier is developed using GENIE-simulated charged-current interactions in the 0.1–4.0 GeV energy range and detector-smeared leptonic and hadronic observables, including reconstructed inelasticity, neutron multiplicity, visible lepton energy, visible hadronic energy, and event-topology variables. The resulting classifier achieves a preliminary AUC of 0.78 for neutrino-enriched and antineutrino-enriched samples. The additional neutrino–antineutrino discrimination improves sensitivity to matter effects and CP-violating oscillation asymmetries, yielding a preliminary CP-violation sensitivity approaching $2\sigma$ for favorable values of $\delta_{CP}$ in a 10-year atmospheric-neutrino exposure. Sensitivities are evaluated using an Asimov dataset and a binned $\chi^2$ likelihood framework incorporating liquid scintillator detector smearing and atmospheric-neutrino systematic uncertainties.

Speakers: DEK HAO LIEW, Mohammad Nizam (Xiamen University Malaysia)

29 Measurement of the Scintillation Light Yield of $\mathrm{CF}_4$ for a High Pressure TPC Used for Reactor Neutrino Detection

A $10~\mathrm{atm}$ $\mathrm{CF}_4$ based Time Projection Chamber (TPC) is under R&D for detecting reactor antineutrinos via neutrino electron elastic scattering $(\nu - e^- \to \nu - e^-)$. The physics goals are to precisely measure the antineutrino spectrum below the inverse $\beta$ decay threshold and to constrain the neutrino magnetic moment. This requires both high energy resolution and excellent spatial resolution. Three dimensional reconstruction of electron recoil tracks in the TPC relies on the concurrent detection of scintillation light and drifting electrons, with the light yield of $\mathrm{CF}_4$ being a critical factor in setting the detector energy threshold.
We have built a dedicated setup to characterise the scintillation response of $\mathrm{CF}_4$ under controlled gas pressure and temperature, using an $ ^{241}\mathrm{Am} $ $\alpha$ source ($5.49 ~\mathrm{MeV}$) and its $59.5~\mathrm{ KeV}$ X-ray emission. Our measurements show that the light yield increases with decreasing temperature, with a pronounced enhancement around $250~\mathrm{K}$. Although the yield generally decreases with rising pressure, cooling to $250~\mathrm{K}$ at $10~\mathrm{ atm}$ restores the light yield to a level exceeding that at room temperature. This poster presents the experimental setup and the observed pressure and temperature dependent light yield, demonstrating that cryogenic operation can significantly improve the scintillation performance of high pressure $\mathrm{CF}_4$ for low energy electron recoil detection in reactor neutrino experiments.

Speaker: Dr 牛苑好 （Yuanhao Niu) (山西大学理论物理研究所 & 中国科学院高能物理研究所)

30 Michel electron tagging efficiency in Water Cherenkov Detectors

Accurate reconstruction of pion production is essential for neutrino oscillation measurements in water Cherenkov detectors, where undetected or poorly reconstructed pions can bias neutrino energy estimation and event interpretation. This poster presents studies of pion-induced signatures in Cherenkov detectors, with a focus on recovering the decay electron from the π → μ → e decay chain to improve reconstruction efficiency. Improved sensitivity to these secondary particles can enhance particle identification and overall event reconstruction performance.

Speaker: Loris Martinez (IFAE)

31 Neural Network-Based Waveform Reconstruction in JUNO

Jiangmen Underground Neutrino Observatory (JUNO) is a multi purpose 20 kton liquid scintillator detector located in southern China. A primary physics goal of JUNO is to determine the neutrino mass ordering using reactor antineutrinos. Achieving this goal critically depends on the detector’s excellent energy resolution, which is directly influenced by the accuracy of waveform reconstruction from the 17,612 20 inch PMTs. This poster introduces a neural network-based, data driven waveform reconstruction method using calibration data. This approach helps reduce the charge smearing effect and further improve the energy resolution.

Speaker: Zhangming Chen

32 Production, Transport and Optical Optimization of Secondary μ⁺ Beams in HFRS

This study investigates the production, transport, and optical optimization of secondary μ⁺ beams in HFRS using an integrated G4Beamline–MAD-X model incorporating the graphite target, two-stage separator, key focal planes, and the MF6 exit. Comparisons of forward π⁺ production from ¹⁶O and ¹⁸O beams at different energies show that ¹⁸O at 4.26 GeV/u provides the highest yield and the strongest high-momentum component, exceeding the corresponding ¹⁶O yield by approximately 12.8% before angular selection and 15.8% after acceptance cuts. Compressing βy in the dominant loss regions increases the normalized μ⁺ flux from 1.1×10⁶ to 1.9×10⁶, while shifting the principal bottleneck from the PREQ789 and B910 regions to 60–70 m. Further optimization should therefore combine focal-plane matching, staged magnetic rigidity, realistic apertures, edge fields, and higher-order optics to improve flux, purity, beam size, and local-loss control simultaneously.

Speaker: jinhe cui (Institute of Modern Physics)

Cui Jinhe NuFact.pdf

33 Quantum Fisher Information as a Probe of Parameter Sensitivity in Long-Baseline Neutrino Oscillations

We investigate Quantum Fisher Information (QFI) as a measurement-independent measure of parameter sensitivity in three-flavor neutrino oscillations. Focusing on the $\nu_\mu \rightarrow \nu_e$ appearance channel, we evaluate the QFI for the leptonic CP-violating phase $\delta_{\rm CP}$, the atmospheric mixing angle $\theta_{23}$, and the atmospheric mass-squared difference $\Delta m_{31}^{2}$ as functions of the baseline-to-energy ratio ($L/E$) using the latest NuFit-6.0 global-fit parameters.

Our results reveal distinct sensitivity patterns for the three oscillation parameters. The QFI for $\delta_{\rm CP}$ and $\theta_{23}$ exhibits two maxima corresponding to the first and second oscillation maxima, whereas the QFI for $\Delta m_{31}^{2}$ shows a single broad maximum at intermediate $L/E$. The corresponding sensitivity hierarchy indicates that $\Delta m_{31}^{2}$ can be determined with the highest intrinsic precision, followed by $\theta_{23}$ and $\delta_{\rm CP}$. We further find that these QFI profiles are robust against current variations in the global-fit oscillation parameters.

Our study demonstrates that QFI provides a useful quantum-information framework for identifying the optimal $L/E$ regions for oscillation parameter estimation and for assessing the fundamental precision limits of current and future long-baseline neutrino experiments.

Speaker: Dr Bhavna Yadav (Wilczek Quantum Center, SIAS, USTC)

34 Research on the Application of GEM Detectors in Neutrino Elastic Scattering Measurements

This poster presents the developmental progress of a time projection chamber (TPC) detector based on gas electron multipliers (GEMs) as the key amplification component. The detector is designed to enable high-precision measurements of the reactor neutrino energy spectrum below the inverse beta decay (IBD) threshold, and to facilitate studies of physics topics such as the neutrino anomalous magnetic moment, mixing angles, and sterile neutrinos. Its operational principle relies on detecting the recoil electron tracks and energies resulting from neutrino scattering off target nuclei, thereby allowing a precise reconstruction of the neutrino energy. To meet these objectives, the detector must simultaneously achieve excellent three-dimensional position resolution and energy resolution, with the capability to record both positional and energy information of scattering events. For signal readout, this work proposes a hybrid detection scheme employing GEMs in conjunction with silicon photomultipliers (SiPMs): the GEMs provide the high electric field strength required for electron multiplication, while the SiPM array enables the reconstruction of both energy and position by detecting the scintillation photons generated during the GEM multiplication process. This poster reports the preliminary test results of this hybrid scheme, including the energy response measurements using a ⁵⁵Fe radioactive source, as well as a comparative analysis of the detector's energy resolution performance under various configurations.

Speaker: 徐靖桓 （Jinghuan Xu) (广西大学 & 中国科学院高能物理研究所)

35 Revival of the Reactor Antineutrino Anomaly

The Reactor Antineutrino Anomaly (RAA)—a long-standing discrepancy between the measured and predicted antineutrino flux—has been a cornerstone in the search for light sterile neutrinos. In recent years, the anomaly was partially attributed to uncertainties in reactor flux models, particularly the 235U contribution. However, new experimental results, most notably from the BEST gallium experiment, along with updated flux evaluations, have sparked a "revival" of the RAA.
This poster reviews the latest developments in this field, highlighting how the combined evidence from reactor and gallium experiments challenges a purely model-based explanation. We explore the renewed case for the sterile neutrino hypothesis and discuss the critical role of upcoming high-precision neutrino experiments in resolving this mystery.

Speaker: 张荣凭 (Rongping Zhang)

36 Simulation and Analysis Framework of the muEDM Experiment at PSI

The muEDM experiment at the Paul Scherrer Institute (PSI) aims to measure the muon electric dipole moment (EDM) - a charge-parity (CP) violating observable - with an unprecedented final sensitivity of 𝜎(𝑑𝜇 ) ≤ 6 × 10−23 𝑒 ⋅ 𝑐𝑚 using the frozen-spin technique. This sensitivity, an improvement of over three orders of magnitude compared to the current limit, would probe beyond-Standard Model new physics and provide insights towards the matter-antimatter asymmetry of the Universe.
We present the comprehensive physics simulation framework developed for the muEDM experiment, built upon Geant4-based simulation toolkits. The framework simulates the full spin dynamics of muons in the storage region, incorporating the muon anomalous magnetic moment and EDM effects in the presence of electric and magnetic fields. The simulation includes the three-dimensional field maps of the storage solenoid, correction coils, weakly focusing fields, and the frozen-spin electric field, enabling detailed studies of spin precession and storage efficiency. The core deliverable of the framework is a robust conversion factor that relates the measured time-dependent asymmetry of decay positrons to the underlying EDM signal. This conversion factor can be applied to study various physics effects, including systematic uncertainties from field imperfections, detector asymmetries, and beam dynamics, as well as to evaluate the sensitivity to potential new physics signatures beyond the Standard
Model.
The analysis framework demonstrates the functionality of the reconstruction chain using truth-level studies, extracting the EDM from the time-dependent asymmetry in the decay positron distribution. Validation against beam test data confirms the reliability of the simulation. The framework enables systematic studies of the experiment's sensitivity, evaluation of false EDM effects from field imperfections and detector asymmetries, optimisation of the frozen-spin condition for Phase-I, and to study the sensitivity to new physics signatures beyond the Standard Model.

Speaker: Guan Ming Wong (Tsung-Dao Lee Institute, SJTU)

37 Simulation Studies for the Development of the IWCD Outer Detector

The Intermediate Water Cherenkov Detector (IWCD) will be constructed approximately 1 km downstream of the J-PARC neutrino beam target to improve neutrino oscillation measurements in Hyper-Kamiokande by reducing systematic uncertainties, particularly those associated with neutrino interaction cross sections. In this study, simulations were conducted to evaluate the performance of and optimize the design of the Outer Detector (OD). The OD is used to identify entering muons and other particles, as well as muons produced inside the Inner Detector (ID) that penetrate the OD. In the simulations, several OD design parameters, including the number and arrangement of PMTs, the reflectivity of the white reflective sheets attached to the OD surface, and the water transparency, were varied, and the numbers of hit PMTs and detected photoelectrons were compared. The results show that variations in Tyvek reflectivity have a larger impact on the detector response than changes in water transparency. To test the integrated detector system and validate the design and performance of the IWCD, including its response to entering muons, a prototype water-tank test is planned at J-PARC. This poster presents the current status of the water-tank test and the related simulation studies.

Speaker: Chisako ISE (Tokyo University of Science)

38 Status of the exclusive muon neutrino charged-current cross section measurement with one proton and one muon in the final state at the NOvA near detector

Understanding neutrino-nucleus interactions is important for reducing systematic uncertainties in precise measurements of neutrino oscillation parameters. These interactions can be studied in NOvA, a long-baseline neutrino experiment that measures electron neutrino appearance and muon neutrino disappearance. The NOvA Near Detector, located ~ 1 km from the beam target, records a high statistics of neutrinos with energies peaking at ~ 2 GeV. The high rate of neutrino interactions provides an opportunity to study various neutrino processes and nuclear effects. Transverse kinematic imbalance (TKI) variables are sensitive to nuclear effects with minimal dependence on neutrino energy, making them useful variables for constraining nuclear models. Here, we present the current status of proton momentum reconstruction in the NOvA Near Detector for the measurement of the muon neutrino charged-current cross section with a muon and a proton in the final state, using TKI variables.

Speaker: Ritesh Kumar Pradhan (Indian Institute of Technology, Hyderabad)

39 Top Drift Electronics: Architecture and Production for DUNE’s Far Detector Vertical Drift Module

The Deep Underground Neutrino Experiment (DUNE) represents the next frontier in particle physics, aiming to unlock the mysteries of the neutrino sector through advanced detector technology. The Vertical Drift (FD-VD) is one of the four planned DUNE Far Detector (FD) modules. It features an innovative architecture that replaces traditional wire anodes with perforated printed circuit board (PCB) based Charge Readout Planes (CRPs). In this vertical drift configuration, the active volume is split into two symmetric 6.5-meter drift regions separated by a central horizontal cathode, where ionization electrons drift vertically under the electric field.

One of the defining features of the FD-VD design is the Top Drift Electronics (TDE) system, which instruments the upper anode planes. The TDE features a cold-accessible architecture that permits the "hot swapping" of components during operation without breaching the argon volume. This solution is optimized for the top-drift CRPs, which are suspended to the cryostat roof providing the full accessibility to the electronics throughout detector lifespan. The performance of the TDE has been extensively validated using large-scale prototypes at the CERN NP02 cryostats. These campaigns demonstrated very low intrinsic noise levels along with long-term stable performance.

Following these successful demonstrators, the TDE has now moved into its industrial production phase, involving the large-scale manufacture quality control of TDE components. This contribution will review the technical architecture of the TDE, summarize performance milestones from the CERN prototypes, and report on the current status of electronics production for the final detector installation.

Speaker: Karishma Dhanmeher (Institute of Physics of the 2 Infinities of Lyon, France)

Tuesday, September 1

Plenary: Plenary (Tuesday AM-1)

40 Latest Results from the Search for a ν̄ₑ Excess in the JSNS2 Experiment

The JSNS2 (J-PARC Sterile Neutrino Search at the J-PARC Spallation
Neutron Source) experiment searches for neutrino oscillations over a
baseline of 24 m, targeting Δm² values around 1 eV². Its primary goal is
to provide a direct test of the LSND anomaly.
The experiment has carried out physics runs from 2021 to 2026,
accumulating a total exposure of 6 × 10²² protons on target (POT) at J-
PARC.
The first results from the search for a ν̄ₑ excess, based on the 2022
physics run data set (0.8 × 10²² POT), were recently published. Since
then, the analysis has been extended to include the 2024 physics run
data set, corresponding to a total exposure of 2.0 × 10²² POT. In this
talk, the latest results will be presented.
The results will be compared with expectations from sterile-neutrino
oscillations as well as with a model-independent prediction obtained by
directly scaling the LSND anomaly.

Speaker: Dongha Lee (KEK)

41 Experimental Landscape of Neutrino Scattering Physics

A precise understanding of neutrino interactions is essential for fully exploiting the physics potential of current and next-generation neutrino experiments. In particular, uncertainties in neutrino–nucleus interactions and nuclear effects are becoming increasingly important as oscillation measurements enter the precision era. At the same time, measurements of neutrino scattering provide unique information on nucleon and nuclear structure and offer opportunities to search for physics beyond the Standard Model.

This talk will review the current experimental landscape of neutrino scattering physics. Recent results from accelerator-based neutrino experiments will be presented, with emphasis on measurements of inclusive and exclusive interaction channels, final-state particle kinematics, and the role of nuclear effects. The experimental techniques used to detect low-momentum protons, neutrons, and pions will also be discussed, together with progress in detector technologies and analysis methods.

The complementarity of measurements using different neutrino energies, target nuclei, and detector technologies will be highlighted. Particular attention will be given to comparisons between experimental data and neutrino-interaction models and to the remaining challenges in reducing systematic uncertainties for precision oscillation measurements. Finally, prospects for upcoming measurements and future experimental programs will be discussed.

Speaker: Tatsuya Kikawa (Kyoto University)

42 MicroBooNE Status

MicroBooNE Status

Speaker: Prof. Fan Gao (UCSB)

10:30 AM Coffee Break

Plenary: Plenary (Tuesday AM-2)

43 ProtoDUNE: Paving the Way to DUNE

Since 2018, the ProtoDUNE programme at CERN has been the cornerstone of the DUNE development effort, providing large-scale prototypes where detector technologies, infrastructure, operational procedures, and analysis and calibration techniques are tested and validated under realistic conditions. With two generations of prototypes already successfully operated and a third generation in preparation, ProtoDUNE has been fundamental in reducing technical risks and establishing the guidelines for the construction and operation of the DUNE far detectors. Beyond its technological mission, ProtoDUNE has delivered a rich physics programme: neutrino, beam and cosmic-ray data have provided valuable insight into detector response, reconstruction performance, and hadronic interactions, all of which are essential to achieving DUNE's scientific goals. This plenary talk will review the status and achievements of the ProtoDUNE programme and discuss its future role in maximizing the scientific reach of DUNE.

Speaker: Miguel Angel Garcia Peris (University of Manchester)

44 DUNE Status

DUNE Status

Speaker: Prof. Jingbo Wang (South Dakota School of Mines and Technology)

45 Upgrade Plans for the Fermilab Accelerator Complex

The Fermilab accelerator complex has been operating for over half a century. For many years, the centerpiece of the lab's program was the Tevatron proton-antiproton collider, but beginning in the late 1990, the lab began to develop a high intensity program, aimed at neutrino and rare process physics. With the shutdown of the Tevatron in 2011, this became the primary focus of the lab. This talk will summarize the current state of the lab and discuss plans for the future, but approved and tentative. The main parts of this plan are the PIP-II linac, which will replace the largely original linac currently in operation, and the new LBNF line being added to support the DUnE Experiment.

Speaker: Prof. Eric Prebys (University of California, Davis)

12:30 PM Lunch

WG1+WG5 — Anomalies, Steriles & Non-Standard Interactions

46 Investigations of the MiniBooNE anomaly and sterile neutrino search with MicroBooNE

MicroBooNE uses a liquid argon time projection chamber (LArTPC) detector to investigate the observed anomalous low energy excess (LEE) of single electromagnetic shower events reported by the MiniBooNE experiment. By leveraging the LArTPC technology's ability to distinguish electron and photon electromagnetic showers, MicroBooNE is able to thoroughly test a number of hypotheses for the origin of the LEE. After five years of data taking from two accelerator beamlines at Fermilab, MicroBooNE has recently published results testing explanations for the MiniBooNE anomaly, including three single-photon searches spanning multiple underlying processes and topologies, a search for the photon-like signature of an electron-positron pair produced by dark neutrinos, an electron neutrino search utilizing the full 5-year dataset collected with the Booster Neutrino Beam (BNB), and a 3+1 sterile neutrino oscillation analysis leveraging both the BNB and Neutrinos at the Main Injector (NuMI) beamlines. This talk will present these results and prospects for future meawsurements.

Speaker: David Caratelli (UC Santa Barbara)

47 Results from the stage one of the DANSS experiment

The DANSS reactor antineutrino spectrometer is located in close proximity to the power reactor at the Kalinin NPP (Russia). A lifting platform allows the detector position to be changed in the range of 11–13 m from the reactor core. More than 10M neutrino events and the long-term experiment operation, covering 5 complete fuel campaigns, provide DANSS with rich experimental data, which is used for both fundamental and applied studies. Our results include:

• the most stringent limit for sterile neutrinos at $\Delta m^2\sim 1 ~\text{eV}^2$;
• new limits for Large Extra Dimensions;
• a precise measurement of the $^{235}$U to $^{239}$Pu neutrino yield ratio;
• the first precise monitoring of an industrial reactor’s power and fission fractions;
• extraction of the observed spectra of the main fissile isotopes $^{235}$U and $^{239}$Pu, as well as the unfolding of these spectra into the antineutrino energy domain;
• a high energy tail of the reactor antineutrino spectrum.

DANSS has been stopped for a major upgrade with the main aim to dramatically improve the energy resolution. New scintillation detectors will feature 8 WLS fibers (YS-2 by Kuraray) with double-side SiPM readout. The average light yield of the new detectors is 200 ph.c. per MeV. The upgraded detector will also have a 70% larger fiducial volume, providing a counting rate of about 10k neutrino events per day at the closest position.

Speaker: Nikita Mashin (LPI RAS)

48 What oscillations can't see: probing NSI with neutral currents channels in accelerators

Neutrino oscillation experiments probe matter effects induced by non-standard interactions (NSI), but the sensitivity is confined to specific combinations of the underlying operators — leaving orthogonal directions in parameter space completely unconstrained. We show that neutral-current (NC) event rates at long-baseline experiments offer a direct handle on these blind directions, since the same operators that modify the matter potential also shift the NC cross section on nuclear targets. Using existing NOvA data and projections for DUNE, we demonstrate that the joint analysis of charged-current and neutral-current samples breaks degeneracies among correlated NSI parameters for the first time in a terrestrial experiment. This complementarity provides coverage of regions in the NSI parameter space that remain degenerate in oscillation-only analyses and that coherent elastic neutrino–nucleus scattering (CEνNS) measurements cannot yet resolve.

Speaker: Joao Paulo Pinheiro (TDLI)

49 Constraints on non-standard neutrino interactions from Borexino extended data-set

The current experimental framework does not entirely exclude the possibility of weak-strength non-standard interactions (NSIs) between neutrinos and leptons. These interactions are classified into two types: Neutral Current (NC) and Charged Current (CC). NC NSIs affect neutrino propagation through matter, while CC NSIs are crucial for the production and detection of neutrinos. The Borexino experiment, located at the Laboratori Nazionali del Gran Sasso (LNGS), excels in detecting solar neutrinos through neutrino-electron elastic scattering in a ~280-ton liquid scintillator target. This setup is particularly suited for identifying signatures of such non-standard interactions. In this poster, we present our latest constraints on NSIs with data from Borexino Phase-II and Phase-III. A more general analysis that includes all possible off-diagonal NSI terms is presented for the first time, providing a comprehensive exploration of the NSI parameter space associated with the flavors of the incoming and outgoing neutrinos.

Speaker: 孙光豹 (Guangbao Sun) (Wuhan University)

WG2 — Interaction Theory & Event Generators

50 Beyond the Inclusive Picture for Multinucleon Knockout in Neutrino-Nucleus Scattering

The precise measurement of neutrino properties is among the highest priorities in fundamental particle physics. Accelerator-based neutrino experiments provide a unique framework for such studies, providing oscillation measurements and hints of the CP violation in the leptonic sector. However, since these experiments rely on the interaction of neutrinos with bound nucleons inside atomic nuclei, understanding the underlying nuclear physics of the target response constitutes a challenging source of uncertainty. Modeling neutrino-nucleus scattering processes is a complex many-body problem, traditionally performed in the independent-particle picture, focusing on the quasielastic neutrino-nucleon interactions or the excitation of nucleon resonances. Improving our knowledge of such cross sections to the required percent-level precision involves conducting research beyond the first approximation, incorporating the effects of nucleon correlations and multinucleon knock-out processes.
In this talk, we present recent advancements from a microscopic, quantum-mechanical framework, where both the bound and scattering hadronic states are governed by a non-relativistic nuclear mean-field potential. Building upon extensive validation against inclusive electron-scattering data, where we show how short-range correlations (SRC) and meson-exchange currents (MEC) provide necessary contributions to describe the quasielastic and dip regions, we extend this formalism to neutrino-induced multinucleon knockout. We then discuss the consequences of proper Distorted Wave Impulse Approximation (DWIA) modeling on exclusive observables. Finally, we address the critical bottleneck of implementing such computationally intensive, exclusive cross section models into Monte Carlo event generators.

Speaker: Kajetan Niewczas (École polytechnique, IN2P3-CNRS, Laboratoire Leprince-Ringuet, France)

51 Duality and Nuclear Medium Effects in Weak Structure Functions at Low $Q^2$

In the neutrino/antineutrino energy region of 1-3 GeV, inelastic processes contribute significantly
to neutrino interaction event rates at the DUNE experiment.
These processes are mainly dominated by single-pion production, with some contribution from
eta production, kaon production, associated particle production, multi-pion production, etc. Generally, single-pion production is understood as due to the ∆(1232) resonance mechanism. However, in the neutrino energy region (1.5-3.0 GeV), it has been realized that other nucleon resonances like P11(1440), D13(1520), S11(1535), S11(1650), P13(1720), etc. are also important. In this region of energy the principle of quark-hadron duality can be very effectively used to connect the deep-inelastic scattering (DIS) cross section to the cross section in the resonance region. We present the deep inelastic structure functions in the weak interactions at $Q^2$ < 1 $GeV^2$ where parton distribution functions become unreliable. We use the Capella et al. (CKMT) parameterizations for the low-$Q^2$ region.
We present results for nuclear medium effects in weak structure functions at $Q^2$ < 1 $GeV^2$. To take into account the dynamics of the nucleons bound inside the nucleus we use a phenomenological approach at the nucleon level and a field theoretical approach to include Fermi motion, binding energy effects, and nucleon correlations (AMUVal DIS model). This work was supported in part by US DOE grant DE-FG02-94ER40847.

Speaker: Alka Singh (Aligarh Muslim University, Aligarh, Uttar Pradesh - 202002, India)

52 Improved RDWIA CCQE Interaction Modelling with the ED-RMF Nuclear Potential in NEUT

Neutrino oscillation experiments, such as the Tokai-to-Kamioka (T2K) and Hyper-Kamiokande (HK) experiments, are increasingly limited by uncertainties in neutrino-nucleus interaction modelling. For HK, this issue will become increasingly prominent as the greatly increased statistics will result in systematic uncertainties being a dominant limitation on the experiment’s physics scope, with neutrino interaction uncertainties among the largest contributions.

In recent years, significant progress has been made in neutrino interaction event generators through the implementation of more sophisticated neutrino-nucleus interaction models. Notably, a fully exclusive relativistic distorted wave impulse approximation (RDWIA) model using the energy-dependent relativistic mean field (ED-RMF) nuclear potential has been implemented in the NEUT event generator [J. McKean et al., Phys. Rev. D 112, 032009, R. González-Jiménez et al., Phys. Rev. C 101, 015503]. The model provides a fully exclusive and unfactorised calculation of the differential cross section, allowing more accurate modelling of lepton-nucleon correlations and elastic final-state interactions that were not previously described by the NEUT intranuclear cascade model.

At the same time, recent developments in lattice quantum chromodynamics (LQCD) have motivated renewed scrutiny of the axial form factor used in neutrino-nucleus interactions. While most generators employ a dipole parameterisation governed by a single axial mass parameter, LQCD calculations provide alternative parameterisations based on the $z$-expansion formalism. Incorporating this additional flexibility is therefore important for assessing the model dependence of neutrino–nucleus cross-section predictions.

In this talk, I will present recent improvements to the RDWIA model within the NEUT event generator that address these concerns. These include the addition of two-body current contributions to one-particle one-hole final states as well as the ability to vary the axial form factor, which was not available in the previous implementation of the model. I will discuss the impact of these changes on comparisons to inclusive and semi-inclusive cross-section data, showing how the combined effects of axial form factor variations and two-body current contributions can introduce tension with existing measurements depending on the kinematic region. In addition, I will present a detailed study of NEUT nuclear models using the JSNS$^{2}$ kaon decay-at-rest measurement of the missing-energy differential cross section at a single neutrino energy. Together, these studies highlight the need for continued improvements to the nuclear models used alongside interaction models in current and future oscillation analyses.

Speaker: Seisho Abe (University of Tokyo)

53 Radiative corrections in neutral-current (anti)neutrino-nucleon elastic scattering at $\text{GeV}$ energies

We introduce radiative corrections in neutral-current (anti)neutrino-nucleon elastic scattering at $\text{GeV}$ energies within the effective field theory framework. We factorize cross sections into soft and hard functions, clarify the (anti)neutrino flavor dependence at both amplitude and cross-section levels, and improve the quantum chromodynamics (QCD) contributions to low-energy neutral-current processes. In particular, we find that the radiative corrections reach a magnitude comparable to the contributions from the strange quarks. In addition, we confront our results with the experimental data from BNL E734 and MiniBooNE, and provide further implications for extracting information on the axial-vector structure and strangeness content of the nucleon.

Speaker: Yi Chen (Tsinghua University)

WG3+WG4 — Muon Sources & Beams

54 Status and future plans for the Muon Source Program at HIAF

The High Intensity heavy-ion Accelerator Facility (HIAF), scheduled to commence operations in 2026, could deliver muons with energies reaching the GeV scale, offering unique advantages for both applied and fundamental research. In the realm of muon imaging, GeV-energy muons provide significantly higher penetration depth. This enables high-resolution muon tomography of large-scale components and dense structures with unprecedented precision. Furthermore, the high flux and energy tunability of the HIAF muon source open new Opportunities for muon physics to searching for physics beyond the Standard Model. This presentation outlines the current status of the HIAF Muon Source Program, details the beamline specifications, and discusses future plans of muon source programs at HIAF.

Speaker: Liangwen Chen

55 Design and Optimization of a Heavy-Ion-Driven GeV Muon Beamline at HIAF

The large acceptance and high magnetic rigidity of the High Energy Fragment Separator (HFRS) at HIAF provide a promising opportunity to develop a tunable GeV-scale muon beam using a heavy-ion-driven production target. We present a stage-by-stage optimization of the existing HFRS optics using G4beamline simulations and a differential evolution algorithm. The objective function accounts for useful muon yield within the required momentum acceptance, pion decay along the beamline, particle contamination, phase-space quality, and downstream transmission. Particular attention is paid to avoiding local improvements that result in particle losses in subsequent beamline sections. The optimized performance is evaluated against the original HFRS optics, with the aim of maximizing the final usable muon flux while maintaining acceptable beam purity and transport quality. This work provides a systematic approach to adapting an existing high-rigidity fragment separator for high-energy muon production, purification, and transport.

Speaker: Ruihu Zhu (Institute of Modern Physics, Chinese Academy of Sciences)

56 COMET Phase-$\alpha$: Validation of the Muon Transport System for a Muon-to-Electron Conversion Search at J-PARC

The COMET experiment at J-PARC searches for the charged-lepton-flavour-violating process of coherent muon-to-electron conversion in a muonic atom, $\mu^- N \to e^- N$, with a target single-event sensitivity of $O(10^{-17})$. Its beamline is designed to transport low-energy negative muons produced by a high-intensity proton beam with high efficiency and to maximise the number of stopped muons in the downstream stopping target. A key element of this system is the Muon Transport Solenoid (MTS), a curved superconducting solenoid that provides charge and momentum selection while guiding the selected negative muons to the experimental area.

COMET Phase-$\alpha$ was carried out in 2023 as the first proton-beam commissioning campaign of the COMET facility. In this campaign, proton-beam injection and secondary-particle transport were commissioned. In particular, negative-muon transport through the MTS was demonstrated for the first time at the facility. This talk reports the validation of the muon transport system, focusing on measurements of the negative-muon beam in the downstream experimental area using a Range Counter (RC).

The RC measures decay electrons from negative muons stopped in a copper plate installed inside the detector, and reconstructs the number of stopped muons from the decay-time distribution. By varying the thickness of graphite degraders placed upstream of the RC, the incident momentum acceptance for stopped muons was changed, allowing the negative-muon momentum spectrum to be reconstructed from data taken under multiple conditions. In addition, position-scan measurements were performed to evaluate the spatial distribution of the beam in the experimental area.

The measured momentum spectrum was broadly consistent with the shape expected from the MTS configuration. The position scan showed an asymmetric beam profile, interpreted as a characteristic effect of transport through the curved solenoid. Comparisons with Geant4-based simulations, including backward muon production, transport, and detection, showed agreement with the main features of both the momentum spectrum and the spatial distribution at the present level of precision.

These results demonstrate successful proton-beam injection into the COMET facility and negative-muon transport through the MTS, marking an important milestone toward the physics search phase of the COMET experiment.

Speaker: Kou Oishi (High Energy Accelerator Research Organization (KEK))

57 Current Status of the High-Repetition-Rate Electron-Driven Pulsed Muon Source at the SHINE Facility

Precision measurements of muon properties and rare decay processes are ideally performed at repetition rates around 50 kHz, yet existing muon facilities are tied to proton accelerators operating in continuous or low repetition rate pulsed modes, making them mismatched to this requirement. We propose an electron driven muon production scheme at the Shanghai High repetition rate XFEL and Extreme Light (SHINE) facility, exploiting its 8 GeV electron beam at 1 MHz repetition rate with 100 pC per bunch, to deliver the time structure and comparable intensities needed for next generation muon experiments. Simulation studies confirm the potential of this approach for both fundamental muon physics and applied research, while also highlighting key challenges including lower per bunch yield, elevated backgrounds, and the need for novel measurement methods. To validate the concept, we propose a muon yield measurement using a compact vacuum chamber with a stopping target and surrounding scintillator detectors to detect muon decay electrons. The current status of the end to end simulation and the hardware installation progress at SHINE are presented.

Speaker: Mr Jun Kai Ng (Shanghai Jiao Tong University)

WG6 — Near Detectors & Time Projection Chambers

58 Performance results of the new high-angle Time Projection Chambers for the T2K upgrade.

The T2K experiment has recently completed the upgrade of its off-axis near detector, ND280. Two new gaseous High-Angle Time Projection Chambers (HA-TPCs) have been installed above and below the highly segmented scintillator active target, the Super-Fine Grained Detector (SFGD), to precisely track particles emitted at large angles with respect to the beam direction. The two new gaseous detectors feature innovative resistive Micromegas technology, and a field cage composed of thin composite walls. This contribution will provide a detailed description of the new components of the chambers, including the gas system, gas monitoring chambers, and data acquisition system. Additionally, the recently published performance results of the HA-TPCs [1] will be presented including the results of extensive testing using both neutrino beams and cosmic rays, with comparisons between data and Monte Carlo simulations. The new detectors achieve improved spatial resolution and enhanced particle identification capabilities which are crucial for the precision goals of the T2K experiment.

[1] https://doi.org/10.1016/j.nima.2026.171527

Speaker: Camilla Forza

59 First Results of the JUNO-TAO Detector

The Taishan Antineutrino Observatory (JUNO-TAO) is a satellite detector of the Jiangmen Underground Neutrino Observatory (JUNO), located 44 m from the 4.6 GW$_{\mathrm{th}}$ core of Unit 1 of the Taishan Nuclear Power Plant. Its primary goal is a precision measurement of the reactor electron-antineutrino ($\bar{\nu}_e$) spectrum with unprecedented energy resolution, providing a model-independent reference crucial to JUNO's determination of the neutrino mass ordering. Additional physics goals include testing nuclear databases, studying the 5 MeV spectral excess, measuring isotope-specific IBD rates, and searching for light sterile neutrinos. The Central Detector employs 2.8 tonnes of Gd-doped liquid scintillator read out by 4024 SiPM tiles covering ${\sim}95\%$ of the inner surface, operated at $-50^\circ$C to suppress the dark count rate, yielding ${\sim}4500$ photoelectrons per MeV. Detector installation was completed in January 2025, commissioning concluded at the end of 2025, and physics data-taking began in early 2026 with an expected rate of ${\sim}1200$ IBD events per day in the fiducial volume ($R<650$ mm). We report on detector commissioning and early performance, together with first physics results from the initial data-taking period.

Speaker: Giovanni Ferrante (INFN, Section of Milano Bicocca)

60 Physics Performance of the SAND Near Detector in DUNE

DUNE is a future long-baseline neutrino oscillation experiment hosted by Fermilab, USA. It aims to measure neutrino oscillation properties with high precision, supernova and solar neutrinos, and possible signatures of nucleon decay. To measure neutrino oscillation parameters, it uses a beam produced at Fermilab and detects the oscillated neutrinos in a 70 kton Liquid Argon TPC volume (divided in four modules) at Sanford Underground Research Facility (SURF), 1300 km away from the neutrino source. SAND is a component of the near detector complex in DUNE permanently located on-axis, 574 m from the neutrino source, with the goals of measuring the incoming neutrino flux, measuring cross-sections and nuclear effects, and performing a broad range of precision measurements of fundamental interactions and searches for new physics. A key element to achieve the required precisions is a low-density Straw Tube Tracker (STT) integrating removable thin targets of various materials. The detector has been optimised for the “solid” hydrogen target, obtained from the subtraction of interactions on plastic (CH$_2$) and graphite (C) targets. The STT has a momentum resolution of about 3% and an angular resolution close to 1 mrad, allowing an excellent reconstruction of the event kinematics, and a particle identification from dE/dx and transition radiation across the entire tracking volume.

Speaker: Shailesh Pincha (Indian Institute of Technology Guwahati)

61 SPINE Reconstruction Performance in ICARUS for SBN Oscillation Physics

Liquid Argon Time Projection Chambers (LArTPCs) enable precise 3D imaging of neutrino interactions at millimeter-scale resolution, making them a leading technology for accelerator-based neutrino oscillation physics. The SPINE reconstruction chain (Scalable Particle Imaging with Neural Embeddings) leverages Sparse Convolutional Neural Networks for voxel-level feature extraction and Graph Neural Networks for particle-level clustering, forming a unified end-to-end pipeline for neutrino interaction reconstruction. We present the performance of SPINE on the ICARUS detector — a 476-ton LArTPC serving as the Far Detector of the Short Baseline Neutrino (SBN) program at Fermilab — and its critical role in enabling ICARUS’s flagship $\nu_\mu$ disappearance and $\nu_e$ appearance oscillation measurements. Michel electrons from muon decay-at-rest provide a clean, well-understood benchmark for validating reconstruction performance and energy scale calibration, serving as a stepping stone toward the full oscillation analysis.

Speaker: Junjie Xia (SLAC/Stanford University)

3:40 PM Coffee Break

WG1+WG2 — Interactions for Precision Oscillation Measurements

62 How Robust Is the $\delta_{CP}$ Measurement?

Measuring the leptonic CP phase $\delta_{CP}$ and resolving the
$\theta_{23}$ octant are primary objectives of DUNE and T2HK.
We show that two distinct effects can compromise the reliability of
these measurements. First, the poorly constrained $\nu_e$ and
$\bar{\nu}_e$ cross sections allow energy-dependent distortions that
partially mimic the $\delta_{CP}$-dependent spectral modulation,
reducing DUNE's CP-violation sensitivity by up to $\sim\!3\sigma$.
We demonstrate that the proposed $\nu$SCOPE facility at CERN can
recover this loss through percent-level measurements of
$\sigma_{\nu_\mu}$ and the $\sigma_{\nu_e}/\sigma_{\nu_\mu}$ ratio.
Second, complex non-standard interactions (NSI) in propagation ---
motivated by the current $\sim\!2\sigma$ NOvA--T2K tension --- induce
correlated biases in $\delta_{CP}$ and the $\theta_{23}$ octant when
DUNE data are interpreted under the standard three-flavor hypothesis.
Since T2HK is largely insensitive to these propagation effects, a
$\sim\!3\sigma$ discrepancy between the two experiments would
constitute a clear diagnostic of BSM physics. These results highlight
that both external cross-section constraints and baseline
complementarity are essential to ensure a robust and unbiased
determination of the oscillation parameters in the precision era.

Speaker: Joao Paulo Pinheiro (TDLI)

63 Precise Measurement of delta at Accelerator Experiments Using Only Neutrino Sector

Several experiments in the next few years will determine the value of the CP-violating phase $\delta$. In accelerator neutrino experiments, such a measurement is usually performed by comparing the oscillation probabilities in the neutrino and antineutrino sectors to break degeneracies with other oscillation parameters. Such an approach has some downsides, however: for instance, the cross section for antineutrinos is significantly smaller than the one for neutrinos (~1/3), which leads to a lower number of observed events in antineutrino mode.
It is possible, however, to measure $\delta$ even if a single channel is considered, for example, using the spectral information (i.e., studying the oscillation probability at different energies) to break the degeneracies. Moreover, in the next few years, the precision with which most of the mixing parameters will be measured will reach the sub-percent level, and those degeneracies will be less and less relevant. We will discuss the precision that can be achieved by measuring $\delta$ at accelerator neutrinos using only the neutrino sector, considering different scenarios, such as sampling the oscillation probability at different energies, or focusing on the oscillation maximum. We will also discuss how the precision on the other mixing parameters could affect the measurement and change the optimal set-up of the experiment.

Speaker: Emilio Ciuffoli (IMP, CAS)

64 Radiative corrections to inverse beta decay at low energies

We compute electromagnetic radiative corrections in the inverse beta decay at reactor antineutrino energies within the heavy baryon chiral perturbation theory, provide the most accurate cross-section predictions for this process, present a complete error budget, and investigate impact on the energy reconstruction at JUNO. For the first time, we consistently include quantum electrodynamics, chromodynamics, and electroweak contributions and present the positron energy spectrum accounting for radiative corrections. Additionally, we include contributions from virtual pions to inverse beta decay and quantify the relation between the experimental value of the nucleon axial-vector charge and its evaluations within the lattice quantum chromodynamics.

Speaker: Sasha Tomalak (Institute of Theoretical Physics, Chinese Academy of Sciences)

65 Reconstruction and selection of charged-current electron neutrino interactions at ICARUS

After successful operation at LNGS and a major upgrade at CERN, the 760-ton ICARUS T600 detector has been running at Fermilab since 2020, collecting neutrino interactions from the BNB and NuMI beams.
In late 2025, ICARUS reached five years of continuous data taking, demonstrating the maturity of large-scale LAr-TPC technology and its relevance for future experiments such as DUNE.
First physics results from ICARUS include a muon neutrino disappearance search in the BNB and cross-section measurements with the NuMI beam.
This contribution presents progress in the reconstruction and selection of charged-current electron neutrino interactions in the off-axis NuMI beam, where the $\nu_e$ component is significantly enhanced compared to BNB.
Improvements to electromagnetic shower reconstruction have led to obtain a high-efficiency, high-purity sample of quasi-elastic-like charged-current electron neutrino interactions with good energy resolution, strongly rejecting photon-induced backgrounds from $\pi^0$ decays.
Applying this selection to NuMI data shows good agreement with the simulation and establishes a robust, well-understood $\nu_e$ sample, demonstrating the potential of ICARUS NuMI data for precision electron neutrino oscillation and cross-section measurements.

Speaker: Riccardo Triozzi (INFN Padova & Università di Padova)

WG4 — Charged Lepton Flavour Violation I

66 Status of the Mu2e experiment

Mu2e will search for coherent, neutrinoless muon-to-electron conversion in aluminum, $\mu^- + {}^{27}\mathrm{Al}\to e^- + {}^{27}\mathrm{Al}$, a charged-lepton-flavor-violating process whose observation would be unambiguous evidence for physics beyond the Standard Model. The signal is a monoenergetic electron near $104.97\ \mathrm{MeV}$, close to the endpoint of the muon decay-in-orbit spectrum. Mu2e aims to reach a single-event sensitivity of approximately $3\times10^{-17}$, improving on previous conversion searches by four orders of magnitude. This talk will summarize the experimental concept, current detector and DAQ integration status, preparations for Mu2e’s first physics data and future extensions to Mu2e.

Speaker: 周威龙 (Weilong Zhou) (California Institute of Technology)

67 COMET status

The COMET experiment searches for neutrinoless conversion of a muon to an electron at J-PARC, JAPAN. The experiment aims to start the first commissioning of the full-set of its muon beamline together with a set of Phase-I detectors to demonstrate the experimental capability. We recently completed the construction of full magnets, and the preparations of detectors are ongoing. In this talk, we will report the latest status and prospects of COMET.

Speaker: Yuki Fujii (Shiga University)

68 Status of the Mu3e Experiment

The Mu3e Experiment at the Paul Scherrer Institut (PSI) aims to probe for charged lepton flavour violation in the µ⁺ → e⁺e⁻e⁺ decay channel. The Phase-I goal of the experiment will utilise an intense DC muon beam of up to 10⁸ µ⁺/s with a goal of pushing the single-event sensitivity down to 2 × 10⁻¹⁵ on the branching ratio. Achieving this goal necessitates a complex system consisting of an ultra-light tracking system for excellent momentum resolution, fast scintillating detectors for sub-ns time resolution, and a high-rate continuous data acquisition system. The experiment successfully carried out a commissioning run in Summer 2025 with a minimal configuration setup, while preparing for physics data-taking in 2027. This contribution will report on preliminary results from the 2025 commissioning campaign, the current status and activities for the 2026 beamtime, in preparation for the upcoming planned physics run.

Speaker: Afiq Azraei Bin Rishinsa (Heidelberg University (DE))

69 Conceptual Design of the Muonium-to-Antimuonium Conversion Experiment (MACE)

The spontaneous conversion of muonium to antimuonium is one of the most interesting charged lepton flavor violating processes, offering a sensitive probe of potential new physics and serving as a tool to constrain the parameter space beyond the Standard Model. The Muonium-to-Antimuonium Conversion Experiment (MACE) is designed to utilize a high-intensity muon beam, a Michel electron magnetic spectrometer, a positron transport system, and a positron detection system, to either discover or constrain this rare process with a conversion probability of $\mathcal{O}(10^{-13})$. In this talk, we will present the physics motivation, the conceptual design, recent progress in detector prototyping and validation, as well as the proposal of MACE Phase-I, which enables broader searches for other muon cLFV decay channels with high precision.

Speaker: 鲁桂昊 (Guihao Lu) (SUN YAT-SEN UNIVERSITY)

WG5 — Searches Beyond PMNS

70 The SHiP/NA67 experiment at the ECN3 high-intensity beam facility at the CERN SPS

The SHiP/NA67 experiment is a general-purpose intensity-frontier experiment for the search for feebly interacting GeV-scale particles and to perform neutrino physics measurements at the HI-ECN3 (high-intensity) beam facility at the CERN SPS, operated in beam-dump mode, taking full advantage of the available $4\times 10^{19}$ protons per year at 400 GeV. The collaboration is currently optimising the experiment's initial configuration for the commissioning and first physics runs of 2032-2033.
The setup consists of two complementary detector systems downstream of an active muon shield: the scattering and neutrino detector (SND), which includes a light dark matter (LDM) neutrino target with vertexing capability. and the hidden sector decay spectrometer (HSDS), consisting of a 50 m long decay volume followed by a spectrometer, timing detector, and a PID system. BDF/SHiP offers unprecedented sensitivity to the decay and scattering signatures of various new physics models and to tau neutrino physics.

Speaker: Mr Massimiliano Ferro-Luzzi

71 Separating Muons from Pions in LArTPC Data Using Optimal Transport for BSM Dimuon Searches

Searches for beyond the Standard Model (BSM) massive long-lived particles decaying to muon pairs face severe irreducible backgrounds in Liquid Argon Time Projection Chambers (LArTPCs). Standard neutrino interactions regularly produce a muon and a pion in the final state, which are currently indistinguishable in LArTPC data. We address this ambiguity using a novel machine-learning method based on the Optimal Transport (OT) algorithm, adapted from LHC jet-classification techniques. By analyzing full 3D track trajectories, our method exploits distinct event topologies at track ends, where muon/pion decays and nuclear captures diverge. We demonstrate the algorithm’s performance using publicly available MicroBooNE simulation data. The classifier is optimized for high-purity muon identification to ensure robust confidence in potential BSM discoveries. The efficiency gains in muon selection evaluated at a 90% accuracy will be reported.

Speaker: Prof. 罗潇 (Xiao Luo) (University of California Santa Barbara)

72 Simulation studies of Lorentz-violating effects at the DUNE experiment

The Deep Underground Neutrino Experiment (DUNE) is a next-generation neutrino oscillation experiment that will provide new constraints for Beyond Standard Model (BSM) phenomena. Lorentz invariance is one of the fundamental principles of quantum field theory and is closely related to symmetries such as charge, parity, and time (CPT) reversal, which form the foundation of the Standard Model (SM) of particle physics. Nevertheless, several BSM scenarios allow for Lorentz invariance violation (LIV) at high energy scales. In neutrino physics, LIV has been investigated as a possible explanation for anomalies reported by experiments such as LSND and MiniBooNE. Since LIV effects exhibit characteristic dependencies on neutrino energy and propagation baselines, they may be distinguishable from other BSM mechanisms, such as non-standard interactions (NSI). In this work, we perform simulation studies of Lorentz-violating effects at the DUNE experiment. We perform our analysis using the General Long-Baseline Experiment Simulator (GLoBES), with a modified oscillation probability engine that includes LIV contributions and explore the vast parameter space using a novel method based on Ant Colony Optimization (ACO).

Speaker: Andre Steklain (Universidade Tecnologica Federal do Parana)

73 Superluminal Nature of Electroweak Radiation and Non Existence of Neutrinos

We propose a unified representation-theoretic reinterpretation of electroweak decay phenomenology based on tachyonic wavefunctions derived in a recent group theoretic extension of special relativity to include superluminal objects. The starting point is the extended space-time geometry in which the invariant content of a four vector is not $\Delta s^2$, but its modulus $|\Delta s^2|$. Correspondingly, the non-lightlike momentum invariant is $|p^\mu p_\mu|=M^2$, so that ordinary massive and tachyonic sectors (with invariants $p^\mu p_\mu=\pm M^2$ respectively) arise as different representatives of the same extended non-massless representation class. The central hypothesis of this paper is that direct products of electroweak decays are superluminal with respect to any laboratory reference frame and are described by tachyonic wavefunctions, that is, by $SO(2,1)$ unitary irreducible representations associated with spacelike momentum orbits. In order to reconstruct the amplitude of the tachyonic process as measured in the laboratory
reference frame we use equivalence between ordinary subluminal description obtained with wavefunctions coming from Unitary Irreducible Representations (UIRs) of $SO(3)$ (the representation space of the observables seen in the laboratory) and superluminal description obtained with UIRs of $SO(2,1)$ used to represent electroweak decay products wavefunctions. Each electroweak decay product $\mathcal C$ (electron, pion, muon, tau etc.) identifies the observables through which the measured decay process is reconstructed in the laboratory. These observables are mapped in the tachyonic representation space via conjugation with the unitary involution representing the intertwiner between massive and tachyonic representations in the non massless representation class of the extended group. The corresponding (SO(2,1)) amplitude contains a little-group factor and a spatial-translation phase. Its normalized phase admits a cumulant expansion
\begin{equation}
\log F_{\mathcal C,\mathbf n,g}(\tau)
=
-i\tau\kappa_1^{\mathcal C}
-\frac{\tau^2}{2}\kappa_2^{\mathcal C}
+\frac{i\tau^3}{6}\kappa_3^{\mathcal C}
+\cdots,
\qquad
\tau=\frac{c\Delta t}{\hbar}.
\end{equation}
The quantities usually attributed to neutrino physics are here reinterpreted as effective cumulant parameters of tachyonic electroweak amplitudes. Flavor labels $\nu_e,\nu_\mu,\nu_\tau$ are interpreted here not as labels of independent asymptotic particles, but as effective bookkeeping introduced when a tachyonic electroweak amplitude is reconstructed in the laboratory observables representation space; endpoint mass parameters arise from the first cumulant of the expansion; oscillation and short-baseline anomalies are associated with higher phase-curvature and dispersion cumulants; matter effects, CP-like phases, and sterile-neutrino parameters are interpreted as higher-order or medium-dependent corrections to the same tachyonic amplitude.
We use this mathematical structure to interpret the main classes of electroweak phenomenology: Wu-type parity-violating beta decay, KATRIN endpoint measurements,atmospheric and reactor anomalies, short-baseline anomalies, solar matter effects, OPERA-like timing anomalies, and high-energy cosmic neutrino events. The aim is to replace the various neutrinos labels and properties coming from energy lines obtained in spectra of different experiments by a single geometric ansatz and its representation theoretic consequences: electroweak decay products are described by superluminal quantum states, and the observed electroweak phenomenology arises as the cumulant expansion of their (SO(2,1)) probability amplitudes as reconstructed in the laboratory.

Speaker: marco zaopo

WG6 — Novel Detector Technologies

74 Development of 3D-Segmented Scintillator Particle Detector

Plastic scintillator detectors with 3D granularity and sub-nanosecond time resolution provide simultaneous particle tracking, identification, and calorimetry. The 3DET R&D collaboration has developed a novel additive manufacturing technique that enables the monolithic fabrication of finely segmented 3D scintillators, consisting of a matrix of optically isolated scintillating voxels with 3D-printed reflective materials to enhance light confinement. To improve the light yield, different types of reflective filaments have been developed and tested.

Moreover, several matrices of optically isolated scintillating voxels based on boron loaded scintillator are produced and evaluated using thermal neutron sources to study their neutron-capture capabilities.

We present recent developments in reflective filament materials, together with experimental results from prototype characterization studies, including measurements of light yield and optical crosstalk.

This work demonstrates a scalable, cost-effective, and time-efficient approach for the production of next-generation scintillator detectors with arbitrary geometries, enabling compact, modular, and high-performance particle detection systems.

Speaker: Umut Kose (ETH Zurich)

75 Prototype of FASERCal detector at LHC Run 4

One of the major physics goals of the FASER experiment at CERN LHC is to study the highest-energy human-made neutrinos. These neutrinos enable investigations of neutrino interactions at the TeV energy scale as well as rare processes such as charm production. In the upcoming LHC Run 4, the increased luminosity will lead to significantly higher collision rates, providing substantially larger neutrino statistics and enhancing the experiment’s physics potential. However, it will also result in a much higher muon background rate, making detector operation increasingly challenging. To address this challenge while maintaining the physics reach, a new neutrino detector, FASERCal, has been proposed. Its main component consists of modules made of finely segmented plastic scintillator cubes, inspired by the T2K Super-FGD detector design, which provide both tracking and calorimetric capabilities. A novel technology has been developed to glue the cubes together, drastically reducing the complexity of detector construction. A prototype detector consisting of one scintillator module has been successfully built and installed at the FASER site, where it has successfully recorded LHC beam data in a high-rate environment. This talk will present the production, assembly, operation, and data-analysis performance of the prototype, demonstrating the feasibility of the proposed full-scale FASERCal detector for Run 4.

Speaker: Xingyu Zhao (ETH Zurich)

76 TRIDENT's prospects for thermal relics

In this talk I will discuss the dark matter science case for the future TRIDENT neutrino telescope. We have recently performed a sensitivity study for galactic dark matter annihilations and found that TRIDENT will be able to reach the thermal relic target for dark matter for masses between 1-100 TeV. We contextualized this result in the wider search for dark matter by studying a specific dark matter model, exhibiting TRIDENT’s unique potential. Furthermore, our analysis was the first of its kind to account for the stochastic nature of the Galactic plane neutrinos, the measurement of which will be an important astrophysical result in its own right. I will briefly discuss the ongoing work and future directions.

Speaker: Andrew Cheek (TDLI, SJTU)

Wednesday, September 2

Plenary: Plenary (Wednesday AM-1)

77 Accelerator-based Neutrino Physics Program

Accelerator-based Neutrino Physics Program

Speaker: Prof. Nakadaira Takeshi (KEK)

78 NCCR Muoniverse Program

NCCR Muoniverse Program

Speaker: Prof. Angela Papa (PSI/Pisa)

79 Neutrino mass and Neutrinoless Double Beta Decay

Neutrino mass and Neutrinoless Double Beta Decay

Speaker: Prof. Lukáš Gráf (Charles University)

10:30 AM Coffee Break

Plenary: Plenary (Wednesday AM-2)

80 JUNO Detector

Jiangmen Underground Neutrino Observatory (JUNO), the largest liquid scintillator detector ever built, started its physics data-taking in Aug. 2025, aiming to address key questions in neutrino physics such as neutrino mass ordering and precision measurement of neutrino oscillation parameters. JUNO consists of a liquid scintillator central detector, an outer water Cherenkov detector, and an external plastic scintillator top tracker. The central detector is filled with 20 kton high-purity, high-transparency liquid scintillator and is instrumented with 17,596 high-quantum-efficiency 20-inch photomultiplier tubes (PMTs) and 25,587 3-inch PMTs, exhibiting excellent detector performance that meets or surpasses the design objectives. This talk reviews the milestones of JUNO’s construction, and highlights its performance and physics results achieved so far.

Speaker: Yaoguang Wang (Shandong University)

81 J-PARC upgrades for Hyper-K

J-PARC upgrades for Hyper-K

Speaker: Dr Piotr Podlaski (CERN)

12:00 PM Lunch

1:00 PM Excursion

Thursday, September 3

Plenary: Plenary (Thursday AM-1)

82 New physics beyond PMNS

New physics beyond PMNS

Speaker: Shun Zhou (IHEP)

83 Educational Projects at Platform for Muon Science and Technology

As second-generation leptons, muons play an important role in both fundamental research and a wide range of technological applications. The Platform for Muon Science and Technology at Sun Yat-sen University focuses on muon-related research and educational programs aimed at training future experts in the field. In this talk, we will introduce the current status of the platform, including its research projects and education programs. We will also discuss ongoing developments and opportunities for potential collaboration in muon science and technology.

Speaker: 袁意 (Yi Yuan) (中山大学)

84 Neutrino Scattering Physics

Neutrino Scattering Physics

Speaker: Prof. Huma Haider (Aligarh Muslim University)

10:30 AM Coffee Break

Plenary: Plenary (Thursday AM-2)

85 Neutrino physics at FASER

The FASER is a compact experiment at the LHC, located 480 m downstream of the ATLAS interaction point along the LHC beamline. It aims to study light, weakly interacting particles produced in the proton collisions at the LHC in the forward region, including exotic particles such as dark photons predicted by some Beyond-the Standard-Model (BSM) models, as well as high energy neutrinos. By detecting for the first time collider-produced neutrinos FASER has opened a new window for neutrino physics in the previously unexplored TeV energy range. Using its emulsion-based sub-detector and electronic components , FASER can observe neutrinos of all three flavors originated from proton-proton collisions.
This talk will present the status of the FASER project, a description of the detector, preliminary results of the LHC Run 3, and future prospects for the high luminosity Run 4, with an emphasis on the experiment’s contribution to TeV scale neutrino physics.

Speaker: Yury Gornushkin (JINR)

86 ESSnuSB Status

ESSnuSB Status

Speaker: Prof. Leon Halić (Ruđer Bošković Institute)

12:00 PM Lunch

WG1 — Long-Baseline Oscillations

87 Latest T2K Oscillation Results: New Data and Analysis Improvements

The T2K (Tokai to Kamioka) experiment is a long-baseline neutrino oscillation experiment that studies accelerator-produced muon neutrino and antineutrino oscillations over a 295 km baseline from J-PARC to the Super-Kamiokande detector in Japan. Its primary goals are the precise measurement of the PMNS mixing angles θ₂₃ and θ₁₃, the mass-squared splitting Δm²₃₂, and the search for CP violation through the δCP phase.

This talk presents the latest oscillation results from T2K, based on a beam exposure of 2.52 × 10²¹ protons on target (POT) in neutrino mode and 1.75 × 10²¹ POT in antineutrino mode. For the first time, this analysis includes Far Detector data collected with the upgraded neutrino beam (representing an additional 0.38 × 10²¹ neutrino POT and 0.12 × 10²¹ antineutrino POT), which delivers a narrower flux shape, higher beam purity, and increased efficiency, resulting in improved sensitivity to oscillation parameters and reduced systematic uncertainties.

The analysis also incorporates a new multi-ring sample and a new neutrino interaction model, implementing a more comprehensive treatment of low momentum transfer interactions, further improving the robustness of the Δm²₃₂ measurement.

These developments mark the beginning of a new era for oscillation analyses in T2K, setting the stage for further improvements as additional data are being collected both at Super-Kamiokande and in the upgraded Near Detector complex.

Speaker: Thomas Leplumey

88 Results from the T2K Near Detector Analysis Fit and Prospects from Near Detector Upgrade Data

T2K is a long-baseline experiment based in Japan and focused on oscillations of neutrinos and antineutrinos. (Anti-)neutrinos from J-PARC are first characterised in the Near Detector (mainly ND280) and, after travelling 295 km, measured in the Far Detector, Super-Kamiokande, in order to extract neutrino oscillation parameters, including the CP-violating phase, within the standard PMNS three-flavour mixing framework. The Near Detector data plays a key role in constraining flux and neutrino interaction models, significantly reducing systematic uncertainties at the Far Detector and therefore having a major impact on the precision of oscillation parameter measurements. To ensure the robustness of these constraints, two independent fitting frameworks are employed to tune the MonteCarlo predictions against the data: the semi-frequentist GUNDAM fitter and the Bayesian MaCh3 fitter, providing cross-validation of the results. For the most recent analysis, new samples covering a wider kinematics phase space, including high angle and backward going tracks, as well as new cross-section parameters have been introduced to improve sensitivity to low and high momentum transfer interactions. Fake data studies are performed in order to test the limits of the T2K interaction and systematics models and to evaluate potential biases in oscillation parameter measurements through fits to alternative interaction model scenarios. These studies are used to estimate possible biases arising from imperfect interaction modelling and to assess whether the current systematic uncertainties adequately cover these effects. In this talk, we will review the latest developments in the T2K Near Detector analysis also in view of the integration of ND280 Upgrade samples into the oscillation framework.

Speaker: Alejandro Nicolas Gacino Olmedo

89 Analysis of Muon Neutrino Interactions in the Upgraded Near Detector ND280 of the T2K Experiment

The Tokai-to-Kamioka (Т2K) experiment is a long-baseline neutrino oscillation experiment designed to precisely measure oscillation parameters and search for CP violation in lepton sector using an intense muon (anti)neutrino beam. The experimental setup consists of the J-PARC proton accelerator complex, the near detector ND280, and the far Super-Kamiokande water Cherenkov detector. Data from ND280 are essential for constraining neutrino interaction model parameters and the initial neutrino flux, which significantly reduce systematic uncertainties in the oscillation analysis. In 2024, ND280 was upgraded with a novel 3D-segmented SuperFGD detector at its core, surrounded by time projection chambers and time-of-flight detectors.The upgrade aims to expand the phase space acceptance for neutrino interaction studies, lower tracking threshold, and enhance timing precision. This work presents the first analysis of muon neutrino interactions in the SuperFGD detector. The results provide the foundation for integrating the upgraded ND280 into the T2K oscillation analysis, thereby improving the overall precision of T2K and laying the groundwork for the next-generation Hyper-Kamiokande experiment at the J-PARC beamline.

Speaker: Daria Fedorova (INR RAS)

90 Status of the Hyper-Kamiokande Experiment

The Hyper-Kamiokande (Hyper-K) is the third generation of underground water Cherenkov detectors in Japan. It will serve as: (1) the far detector for a long-baseline neutrino oscillation experiment for the upgraded, 1.3 MW power, J-PARC muon neutrino/antineutrino beam, and (2) a detector capable of observing proton decays, atmospheric neutrinos, and neutrinos from astronomical sources. The fiducial region of the Hyper-K detector, with a mass of 186 kton, will be instrumented with 20,000 20-inch photomultipliers (PMTs) and 800 multi-PMT modules, each containing 19 3-inch PMTs. Assembly and testing of detector components are underway, and operation is scheduled to begin in 2028. The Hyper-K status, research program, and sensitivities to different processes, including proton decay and CP violation in the neutrino sector, will be presented.

Speaker: Nicholas Latham (King's College London)

WG2 — Cross Sections at Accelerator Experiments

91 Neutrino cross-section results from T2K

T2K is a long-baseline experiment for the measurement of neutrino oscillations. The neutrino flux and neutrino-nucleus cross-sections are measured by a suite of near detectors, including ND280, an off-axis multipurpose magnetised detector, WAGASCI, featuring a water-enriched target at a different off-axis angle, and INGRID an on-axis detector composed of sandwiched layers of iron and scintillator.The near detectors perform a wide variety of neutrino-nucleus cross-section measurements on different targets and for different final states. Such a program, to control systematic uncertainties for T2K and beyond, provides high-quality data to benchmark improved models of neutrino-nucleus scattering.We will review the most relevant cross-section results, including Charged Current (CC) interactions on water, Neutral Current interactions (NC) and electron-neutrino CC interactions with pions in the final state.

Speaker: Pilar Casado

92 Neutrino Interaction Measurements with the SBND Experiment

The Short-Baseline Near Detector (SBND) is a 112-ton scale Liquid Argon Time Projection Chamber (LArTPC) neutrino detector positioned in the Booster Neutrino Beam at Fermilab, as part of the Short-Baseline Neutrino (SBN) program. The detector is currently collecting neutrino beam data. Located only 110 m from the neutrino production target, SBND is exposed to a very high flux of neutrinos and will collect millions of neutrino interactions each year. This huge number of neutrino interactions, with the precise tracking and calorimetric capabilities of LArTPC, enables a wealth of cross section measurements to be made with unprecedented precision. In addition, SBND has the unique characteristic of being remarkably close to the neutrino source and deliberately not perfectly aligned with the neutrino beamline, in such a way that allows sampling of multiple neutrino fluxes using the same detector, a feature known as SBND-PRISM. SBND-PRISM can be utilized to study distinctive neutrino-nucleus interaction channels. This talk will motivate the SBND cross-section physics program, present ongoing measurement efforts, and discuss prospects for the rich program ahead.

Speaker: Bruno Zamorano (University of Granada)

93 Recent neutrino cross section results from MicroBooNE

Making high precision measurements of neutrino oscillation parameters requires an unprecedented understanding of neutrino–nucleus scattering. MicroBooNE is able to perform high resolution imaging of numerous final state topologies resulting from neutrino interactions. This talk will give an overview of MicroBooNE's most recent neutrino cross section results. These include our latest $\nu_{\mu}$ CC pionless result where we measure proton multiplicity probing the modeling of sub-leading proton kinematics for the first time. We will also present our latest measurements of $\nu_{e}$ CC interactions, including new pionless measurements using two different neutrino beams. These help to shed light on the $\nu_{e}$/$\nu_{\mu}$ cross-section ratio that forms a key systematic in neutrino oscillation measurements. Alongside this, we will show MicroBooNE’s first measurement of coherent charged-pion production, a channel that has been proposed as a constraint of neutrino beam fluxes. Finally, we will present MicroBooNE's first measurement of kinematic imbalance in neutral pion interactions, probing the impact of nuclear modeling and the impact of final-state interactions in resonant pion production. Together, these measurements form a comprehensive program exploring the modeling of neutrino scattering on argon, providing critical inputs for upcoming oscillation experiments.

Speaker: Patrick Green (University of Oxford)

94 Status and Plans for Measurements of Neutrino-Argon Interactions at ICARUS

The ICARUS experiment, utilizing Liquid Argon Time Projection Chamber (LAr TPC) technology, has been installed at Fermilab (USA), following its initial operation in Italy and subsequent refurbishment at CERN. ICARUS has successfully been taking physics data at Fermilab since June 2022. While the experiment’s primary objective is to function as the far detector of the Short Baseline Neutrino program (SBN), searching for hints of physics beyond three-flavour PMNS neutrino oscillations, ICARUS also offers other diverse physics capabilities, including searches beyond the standard model and measurements of cross-sections. In addition to being exposed to the common Booster Neutrino (BNB) beamline of the SBN experiment, ICARUS receives neutrinos from the Main Injector (NuMI) beam. Due to the off-axis angle between NuMI and ICARUS, coupled with contributions from both pion and kaon decays to neutrino fluxes, interactions of NuMI neutrinos within ICARUS can be detected over a range of several GeV in energy. Measurements of these interactions present unique opportunities to infer neutrino interaction cross sections on an argon nuclear target within an energy range that overlaps both the SBN oscillation search and a significant portion of the DUNE spectrum. This presentation will summarise the current status of ICARUS’ neutrino cross-section measurements.

Speaker: Alessandro Menegolli

WG4 — Muon g−2 & Electric Dipole Moments

95 J-PARC muon g-2/EDM Experiment

The muon anomalous magnetic moment, $(g-2)_{\mu}$, and the electric dipole moment (EDM) are sensitive probes of physics beyond the Standard Model (SM). Recent measurements of $(g-2)_{\mu}$ show a tension with the SM prediction based on electron-positron collision data, while calculations based on lattice QCD are in better agreement with the experimental value. Clarifying this discrepancy is essential for understanding whether it originates from new physics. In this context, an independent experimental approach with different systematic uncertainties is of particular importance.

We aim to measure $(g-2)_{\mu}$ and to search for the muon EDM using a method different from those employed in the E821 experiment at BNL and the E989 experiment at Fermilab. To achieve this, we utilize the high-intensity proton beam at J-PARC together with a newly developed technique based on a reaccelerated thermal muon beam, which is produced through thermal muonium formation followed by laser ionization and linear acceleration. We have successfully demonstrated the cooling and acceleration of muons, and are advancing the proof-of-principle studies of the key technologies required for the experiment. We report the experimental approach, the current status of each component of the experiment, and future prospects.

Speaker: Yutaro Sato (Niigata Univ.)

96 Studies of Ultra-Slow Muon Production for the J-PARC Muon g-2/EDM Experiment

The ultra-slow muon (USM), developed for the J-PARC muon g-2/EDM experiment, is produced by laser ionization of thermal muonium using 122 nm and 355 nm laser pulses, a process known as muon cooling. Since late 2025, two beam tests have been conducted using the new high-intensity surface muon beamline dedicated to the J-PARC muon g-2/EDM experiment. During these beam tests, extensive studies of the USM production process have been carried out.

This presentation reports recent progress in the USM production study based on these beam tests. A dedicated laser diagnostic system has been developed to characterize and monitor the laser parameters relevant to USM production. Beam-test measurements, including laser parameter scans and long-term stability studies, are presented together with relevant simulation studies to improve the understanding of the USM production process and guide future optimization.

Based on the laser commissioning results, upgrades toward improved performance are underway, including enhanced operational stability, mitigation of laser optics degradation, and improved laser alignment and control strategies. Finally, the future roadmap toward achieving the design laser performance and ionization efficiency will be outlined.

Speaker: 吕濛 (Meng Lyu) (University of Tokyo)

97 Development of Muon Trigger Detector for muEDM experiment at PSI

The muEDM experiment at the Paul Scherrer Institute (PSI) aims to measure the muon electric dipole moment (EDM) with unprecedented sensitivity, targeting a precision of σ($d_\mu$) = 6 × 10⁻²³ e·cm, which represents an improvement by three orders of magnitude over the current limit established by the muon g−2 experiment at Brookhaven National Laboratory (BNL). Central to this effort is the muon trigger detector (MTD) located at the entrance of the solenoid, which enables fast and precise identification of muons within the solenoid storage acceptance. The trigger activates a pulsed magnetic field that guides muons into stable orbits; the stored muons are exposed to a radial electric field enabling the "frozen‑spin" technique, thereby isolating the spin precession induced by the EDM.

The MTD employs plastic scintillators read out by silicon photomultipliers (SiPMs) and comprises two subsystems: a 100‑μm‑thick gate detector for incident muon detection, and an aperture detector that rejects non‑storable muons via anti‑coincidence logic. The electronics must generate the trigger signal within 15 ns to ensure proper storage of the selected muons. For the aperture detector, open‑drain gated wired‑AND logic is adopted to reduce the number of logic gate layers, thereby minimizing propagation delay. For the gate detector, an additional delay module is inserted to delay the gate signal, as the aperture detector is typically hit several nanoseconds later than the gate detector.

This system ensures selective triggering of only storable muons while suppressing background events. An MTD prototype was validated using surface muons at the PSI πE1 beamline, and its performance was assessed by comparing experimental data with Geant4‑based simulation results. This talk presents the key design principles, prototype test results, and the progress made toward achieving the breakthrough sensitivity goal of the muEDM experiment.

Speaker: Mr 黄幸运 (Xingyun Huang) (SJTU)

98 CANTON-μ Proposal: A Next-Generation Muon g−2 Measurement at Sub-0.1 ppm Precision

We propose a next-generation precision measurement of the muon anomalous magnetic moment (muon g−2), at the High Intensity Heavy-Ion Accelerator Facility (HIAF) in China. The project, named CANTON-μ (Coherent Anomalous magNetic momenT ObservatioN with muon), represents the first muon g−2 experiment aimed at surpassing Fermilab precision. It introduces novel approaches based on HIAF's intense pulsed GeV-scale muon beams, particularly for negative-muon polarity. This talk will present expected muon beam intensity at HIAF, establishing the statistical reach and level of systematic control required to achieve a precision of 0.13 ppm in Phase 1, matching the current Fermilab precision, and 0.05 ppm in Phase 2 with the HIAF upgrade. This precision enables stringent tests of the Standard Model with sensitivity to new physics beyond current collider scales, and offers a uniquely sensitive test of CPT symmetry in muon sector, improving existing limits by more than an order of magnitude.

Speaker: 张策 (Ce Zhang) (University of Liverpool)

WG6 — Liquid Argon Detector Technology

99 DUNE LArTPC Vertical Drift technology: Status and Updates

The Deep Underground Neutrino Experiment (DUNE) is a global flagship project designed to resolve open questions in neutrino physics, including charge-parity (CP) violation in the leptonic sector, the neutrino mass ordering, and low-energy astrophysical phenomena such as supernova neutrino bursts. To achieve the large fiducial mass and sub-centimeter spatial resolution for these rare events, the experiment uses modular Liquid Argon Time Projection Chamber (LArTPC) technology at the Far Detector (FD) site. Among the four planned FD modules, the FD-VD (Vertical Drift) module utilizes an innovative design where traditional wire anodes are replaced by perforated printed circuit board (PCB) Charge Readout Planes (CRPs). This vertical drift architecture splits the active volume into two symmetric 6.5 m drift regions separated by a central horizontal cathode that enables ionization charge to drift vertically toward the top and bottom CRPs.

To demonstrate the VD technology, a 1:20 scale LAr mass prototype, ProtoDUNE-VD, has been installed at the CERN Neutrino Platform (NP02). During the August–September 2025 beam campaign, data were collected using CERN's H2-VLE hadron beam, followed by continued data taking with cosmic rays. This contribution will present the current status of the VD technology. In particular, it will highlight the performance of ProtoDUNE-VD and provide updates on the transition from prototyping toward the mass production phase of the FD-VD module.

Speaker: Karishma Dhanmeher (Institute of Physics of the 2 Infinities of Lyon, France)

100 Innovative Power over Fiber Solutions for the DUNE Vertical Drift Photon Detection System

In modern physics, the nature of neutrinos remains one of the major open questions, motivating new experimental efforts to investigate their properties. The Deep Underground Neutrino Experiment (DUNE) is a next-generation international experiment designed to determine the neutrino mass ordering, study CP violation in the neutrino sector, detect neutrinos from astrophysical sources, and search for physics beyond the Standard Model.

Currently under construction in the United States, DUNE will use an intense neutrino beam produced at Fermilab and a Far Detector located $1300$ km away at the Sanford Underground Research Facility. The Far Detector will consist of four $17$-kton Liquid Argon Time Projection Chamber (LArTPC) modules, two with already planned geometry and technology, while the remaining two are still under discussion. Phase I includes one Vertical Drift (VD) detector and one Horizontal Drift (HD) detector. Both designs employ a Photon Detection System (PDS) based on X-ARAPUCA devices instrumented with Silicon Photomultipliers (SiPMs).

In the Vertical Drift module, X-ARAPUCAs are installed on both the detector walls and the cathode to optimize light collection in the active volume. However, powering the devices located on the cathode is challenging because this region operates at high voltage ($-300$ kV), making conventional copper cabling impractical. To address this issue, the DUNE collaboration is developing Power over Fiber (PoF) and Signal over Fiber (SoF) solutions, where both power delivery and signal readout are performed through optical fibers.

This contribution presents an overview of PoF and SoF applications for DUNE and reports on recent tests performed at CERN, where the full PDS was operated in a configuration closely resembling the final detector design.

Speaker: Valeria Trabattoni (Università degli Studi di Milano e INFN Milano)

101 DUNE Far Detector Photon Detection System Validation with ProtoDUNEs

The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline experiment for neutrino physics currently under construction in the US, aiming to measure neutrino oscillation parameters, search for beyond standard model physics, and detect supernova neutrinos. DUNE will include a Near Detector and a Far Detector (FD), located 1300 km away from the ND and 1.5 km underground. The FD will consist of four 17-kton active Liquid Argon Time Projection Chambers (LArTPCs). In Phase I, two modules implementing horizontal (HD) and vertical (VD) drift technologies will be used. To test these technologies, two 750-ton LArTPCs (ProtoDUNEs) were built at CERN and operated over the past two years.

The topology of a neutrino interaction in the LArTPC is reconstructed from the tracks of secondary charged particles, which produce scintillation light and ionization charge carriers during their propagation in LAr. The reference time of the event is provided by the scintillation light, detected by X-ARAPUCA modules. These are photon traps consisting of a box with highly reflective internal walls instrumented with Silicon PhotoMultipliers (SiPMs). Therefore, the FD Photon Detection System (PDS) is critical for the DUNE physics program.

In this talk, the designs of the DUNE PDS for the first two modules are presented, along with first results from ProtoDUNE-HD and ProtoDUNE-VD PDS operations.
The preliminary results demonstrate the successful operation of the PDS, marking a crucial step toward validating the HD and VD designs for the first FD modules.

Speaker: Anna Balboni (University & INFN of Ferrara)

2:55 PM Coffee Break

WG1 — Atmospheric Neutrinos & Phenomenology

102 Atmospheric neutrinos in DUNE

The Deep Underground Neutrino Experiment (DUNE) is a pioneering long-baseline neutrino experiment that will feature multi-kiloton scale Liquid Argon Time Projection Chambers (LArTPCs). Beyond its primary beam neutrino objectives, DUNE's cutting-edge technology offers a unique opportunity to investigate atmospheric neutrinos with unprecedented precision. Atmospheric neutrinos, spanning a wide range of energies and path lengths, provide a rich dataset for probing diverse $L/E$ regimes, offering invaluable insights into the PMNS oscillation parameters. This natural neutrino source provides a highly complementary dataset to DUNE's beam program, helping to break parameter degeneracies and enabling a comprehensive view of neutrino oscillations.
This talk will focus on the latest reconstruction performance and the comprehensive analysis framework for atmospheric neutrinos within the DUNE experiment. Building upon the full simulation and reconstruction chain, which includes detailed evaluations of the hadronic system, energy estimation, and directional reconstruction capabilities, we present the critical next steps toward full oscillation analyses. Specifically, we will discuss the recent, extensive implementation of systematic uncertainties, covering atmospheric flux variations, cross-section models, Earth density profiles, and detector effects. The integration of these systematic constraints demonstrates the high-precision capabilities of DUNE's LArTPC technology and directly sets the stage for upcoming sensitivity studies to standard neutrino oscillations and physics beyond the Standard Model.

Speaker: Pierre Granger (CERN)

103 Improved Calculation of Atmospheric Neutrino Fluxes using the Bartol Model

Next generation neutrino oscillation experiments, such as JUNO, DUNE, and
Hyper-Kamiokande, are positioned to collect unprecedented statistics in neutrino
data, enabling high-precision measurements of oscillation parameters. A major
fraction of the data will consist of atmospheric neutrinos, which allows for
independently extracting oscillation parameters and placing constraints on
neutrino mass ordering by probing the MSW parametric resonance. To make best use
of the data, it is essential to understand and improve the current modelling of
atmospheric neutrino fluxes and their uncertainties.

The Bartol model is a Monte Carlo simulation-based atmospheric neutrino flux
model created in the 1980s for calculating the unoscillated flux at terrestrial
detectors. The original model has become significantly outdated as it uses
physics models which do not reflect recent experimental measurements on e.g.
hadron production cross section or primary cosmic ray fluxes with drastically
improved uncertainties. The geomagnetic field model likewise needs to be updated
to include around 20 years of geomagnetic field observations. In the context of
DSNB searches, there is growing interest in <100 MeV atmospheric neutrino
fluxes, which is outside of the energy range described by the original Bartol
model.

To accommodate for updates to the Bartol model, the codebase has been fully
redesigned from the ground up to facilitate model development. I will
demonstrate that predictions from the new simulation are consistent with
previous results from the Bartol model and cover recent progress towards
addressing the shortcomings of the original Bartol model.

Speaker: Yiwen Yang (University of Oxford)

104 First measurement of geoneutrinos at JUNO

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20-kton multipurpose liquid scintillator detector located at a depth of 650 meters in South China. Although its primary mission is the determination of the neutrino mass ordering, JUNO’s unprecedented target mass and excellent energy resolution offer a unique opportunity to study geoneutrinos with high statistics.
Geoneutrinos, produced by the decay of 238U, 232Th, and 40K (which cannot be detected by JUNO due to their low energy) within the Earth's interior, carry vital information about the planet’s chemical composition and heat sources. Benefiting from the largest ever detection volume for geoneutrinos, JUNO is expected to detect several hundred events per year, significantly surpassing the cumulative statistics of previous experiments such as KamLAND and Borexino.
This talk highlights JUNO’s first geoneutrino analysis using the latest experimental data. We present the measured geoneutrino rate and its implications for geoscience. By comparing our findings with leading geological models, we demonstrate JUNO’s power to discriminate between different mantle compositions.

Speaker: 张荣凭 (Rongping Zhang) (IHEP)

105 Quantum Estimation Perspective on Neutrino Oscillation Measurements

Quantum estimation theory provides a powerful framework to quantify the ultimate precision with which neutrino oscillation parameters can be inferred. In this work, we use the Quantum Fisher Information (QFI) to study the information content associated with the leptonic CP phase $\delta_{\rm CP}$ in long-baseline experiments and the solar parameters $\Delta m^2_{21}$ and $\theta_{12}$ in reactor and solar neutrino experiments. For T2K and NO$\nu$A, we compare the intrinsic QFI of neutrino states with the event-level Fisher information obtained from reconstructed spectra, showing that present measurements extract only a limited fraction of the available quantum information, with reduced efficiency near maximally CP-violating regions. For reactor and solar neutrinos, we show that coherent reactor evolution allows flavor measurements to approach the QFI bound, while solar neutrinos lose the phase-based contribution due to matter effects and decoherence. Consequently, solar experiments are intrinsically more sensitive to $\theta_{12}$ than to $\Delta m^2_{21}$. Our results provide a unified information-theoretic perspective on the precision limits of neutrino oscillation experiments.

Speaker: Neetu Raj Singh Chundawat (Institute of High Energy Physics, Beijing)

WG2 — Precision & Low-Energy Scattering

106 Status and physical program of the vGeN experiment at Kalinin NPP

The vGeN ("nu-GeN") setup is collecting data at Kalinin NPP, 11.1 m from the center of a 3.1 GW reactor core, since late 2019. The aim of the experiment is to measure coherent elastic antineutrino-nucleus scattering (CEvNS) as well as to search for antineutrino electromagnetic properties with a 1.4 kg germanium point-contact detector. The talk presents updated results of the experiment on antineutrino magnetic moment, millicharge and hypothetical millicharged particles. The plans for the setup modification including the NaI-based "Compton veto" and new DAQ system allowing to record waveforms from the germanium detector are discussed.

Speaker: Alexey Konovalov (LPI RAS)

107 CICENNS experiment: A 300kg CsI(Na) detector for CEvNS measurement

Coherent elastic neutrino-nucleus scattering (CEvNS) benefits from the coherent interaction of neutrinos with an entire nucleus at low momentum transfer, resulting in an enhanced cross section that provides a sensitive approach for detecting low-energy neutrinos. The CICENNS (CsI Detector for Coherent Elastic Neutrino-Nucleus Scattering) experiment aims to perform a high-precision measurement of CEvNS using neutrinos from pion decay-at-rest at the China Spallation Neutron Source (CSNS). To achieve this, the CICENNS detector employs a 300-kg CsI(Na) target composed of fifteen 20-kg crystal modules, surrounded by a plastic-scintillator veto system. With this detector configuration, CICENNS aims to precisely measure the CEvNS cross section, while also providing sensitivity to nuclear neutron distributions and physics beyond the Standard Model. Detector construction is nearing completion, and deployment at the CSNS site is planned for later this year. This presentation will cover the detector design and construction, projected physics sensitivities, current status, and plans for deployment and operation.

Speaker: 宋天资 (Tianzi Song) (Sun Yat-sen University)

108 Exploring the electromagnetic properties of neutrinos at a short-baseline reactor neutrino experiment

Upcoming and present reactor neutrino experiments offer a compelling avenue to probe fundamental neutrino properties beyond flavor oscillations. In this talk, I will discuss the physics potential of a short-baseline reactor experiment, inspired by the JUNO-TAO configuration, to investigate neutrino electromagnetic interactions via electron--neutrino elastic scattering (E$\nu$ES). I will present the expected sensitivity to the weak mixing angle, $\sin^2\theta_W$, and to the neutrino charge radius. Furthermore, I will show projected limits on the effective neutrino magnetic moment, $\mu_{\nu}$. Compared to existing reactor neutrino constraints, this experimental setup can achieve competitive and in some cases, leading limits on the electromagnetic properties of neutrinos.

Speaker: Luis A. Delgadillo (IHEP)

109 Neutrino Effects on Atomic Measurements of the Weinberg Angle

Atomic parity violation (APV) provides a unique determination of the weak mixing angle ($\sin^2\theta_W$) at low energies and therefore serves as a powerful precision test of the Standard Model. We show that previous APV calculations omitted a class of one-loop contributions arising from two-neutrino exchange, commonly referred to as "the neutrino force". We compute this contribution to APV and find that its effect is comparable to the current experimental sensitivity. Remarkably, incorporating this previously neglected contribution shifts the APV-extracted value of $\sin^2\theta_W$ toward the Standard Model prediction, thereby alleviating the existing (mild) tension between APV measurements and the Standard Model.

Speaker: Bingrong Yu (Cornell University)

WG4 — Charged Lepton Flavour Violation II & Precision Muon Physics

110 Searches for Charged Lepton Flavour Violation at Belle and Belle II

The Belle and Belle II experiments have collected a $1.6~\mathrm{ab}^{-1}$ sample of $e^+e^-$ collision data at center-of-mass energies near the $\Upsilon(nS)$ resonances. We present searches for the decays $\tau \to \mu\gamma$, $\tau \to \ell\eta$, $\tau\to \ell\pi^0$, and $\tau^-\to \ell^-\alpha$, where $\ell = e$ or $\mu$ and $\alpha$ is an invisible scalar particle. In addition, we present results of searches for $\chi_{bJ} \to e \mu, e \tau$, and $\mu \tau$, as well as $B \to K \ell \tau$ ($\ell = e, \mu$).

Speaker: 李文哲 (Wenzhe Li)

111 Search for rare and lepton-flavor-violating Higgs boson decays at the ATLAS experiment

The Standard Model predicts several rare decay processes of the Higgs boson, including decay to a Z boson and a photon (H->Zgam), decay to a pair of muons (H->mumu), and decay to a pair of electrons (H->ee). The lepton-flavor-violating (LFV) decay of the Higgs boson, on the other hand, is forbidden in the Standard Model but allowed in new physics models. Search for rare and LFV decays of the Higgs boson could provide a stringent test of SM and serve as a powerful probe to new physics. This talk will present several results for Higgs boson rare decay searches based on LHC Run 2 and Run 3 data.

Speaker: Bo Liu (Nankai University)

112 The MUonE Experiment and First Results from the 2025 Test Run

The MUonE experiment, currently under preparation at CERN, aims to measure the running of the electromagnetic coupling $\alpha$ in the elastic $\mu e$ scattering process, from which the dominant hadronic contribution to the anomalous magnetic moment of the muon can be extracted. We present performance results from the Phase 1 MUonE test-beam campaign carried out in summer 2025 at the CERN SPS M2 beamline, using CMS 2S silicon modules exposed to a high-rate 160 GeV muon beam. A description of the full detector used will be given. The talk will highlight the main findings and the status of the ongoing analysis. The results from this test run will give indications on the choices for the final detector dedicated to a high-precision measurement of muon-electron elastic scattering.

Speaker: Mr 高乐耘 (Leyun Gao) (Peking University)

113 Anti-neutrino Nuclear Responses by High Energy-Resolution Gamma-ray Studies Following Ordinary Muon Capture on Molybdenum

Ordinary Muon Capture (OMC) provides a unique experimental avenue to probe the β+ type nuclear responses essential for understanding double beta decays (DBDs) and astrophysical neutrino interactions. This study leverages high energy-resolution gamma-ray spectroscopy to meticulously identify transition channels in enriched and natural molybdenum. By utilizing high-purity germanium (HPGe) detectors, we resolve complex spectra to determine precise branching ratios for (µ, xnν), and (µ, xnpν) particle emission channels. These high-resolution datasets enable the identification of ppb-level elemental impurities for extracting the spin states involves during OMC. Within the framework of the Proton Neutron Emission Model (PNEM), the µ capture strength distribution across the Giant Resonance (GR) region (0–70 MeV) were mapped. In this region, nuclear transitions are predominantly driven by low multipole states (0±, 1±, 2±), with only minor contributions originating from higher multipole states (5±, and 6±). These high-resolution observations serves as crucial benchmarks for theoretical pn-QRPA calculations, and aid in understanding nuclear structure deformations relevant to hypothetical 0νββ decay, providing the critical experimental constraints needed to refine theoretical Nuclear Matrix Elements (NMEs).

Speaker: IZYAN HAZWANI BINTI HASHIM (Universiti Teknologi Malaysia)

WG6 — Simulation, Backgrounds & Low-Energy Performance

114 A Simulation Study of Neutrino-Induced Backgrounds in the Intermediate Water Cherenkov Detector for Hyper-Kamiokande

In the Hyper-Kamiokande experiment, controlling systematic uncertainties is essential to achieve the projected precision of long-baseline neutrino oscillation measurements. To constrain uncertainties associated with neutrino interaction cross sections, the Intermediate Water Cherenkov Detector (IWCD) is being developed as a movable water Cherenkov detector located 870 m from J-PARC along the direction of Hyper-Kamiokande. By changing its vertical position, the IWCD can observe neutrinos under different flux and energy conditions, enabling precise measurements of neutrino interaction cross sections in the sub-GeV region. For such measurements, understanding beam-induced background events is essential. Neutrinos interacting with the surrounding soil and reinforced concrete structures can mimic signal events if they produce secondary particles that enter the Inner Detector (ID) without Cherenkov light being detected in the Outer Detector (OD). Another source of background events is pile-up, where multiple neutrino interactions take place within a few tens of nanoseconds due to the combination of the intense 1.3 MW neutrino beam and materials surrounding the detector.
In this study, Monte Carlo simulations using the SandSim and WCSim software packages were performed to evaluate detector responses to neutrino-induced backgrounds and pile-up events in the IWCD. I quantitatively evaluated the contribution of background events arising from interactions outside the ID to the ID event candidates and investigated their characteristics. This study will be utilized for optimization of the OD configuration and establish effective event-selection criteria by investigating background events that cannot be vetoed by the OD.

Speaker: Akari Oka (Keio Univertsity)

115 9Li/8He estimation and reduction in JUNO

In the Jiangmen Underground Neutrino Observatory (JUNO), cosmogenic muon-induced radioactive isotopes, particularly ⁹Li/⁸He, which undergo β-n decays, produce correlated signals that closely mimic the inverse beta decay (IBD) signature. This constitutes one of the major backgrounds for reactor antineutrino oscillation analyses, with an initial rate of ~60/day before applying any muon veto. This talk presents comprehensive strategies for 9Li/8He reduction and background estimation. To effectively suppress this background, we optimized traditional spatiotemporal veto cuts based on the distance to the parent muon track, the distance to spallation neutrons, and the time elapsed since the muon crossing. Coupled with a robust data-driven IBD efficiency estimation approach, this methodology drastically reduces the 9Li/8He background from ~60/day to ~ 2/day while preserving a high IBD efficiency. In addition, machine learning approaches are investigated as complementary tools for background rejection, demonstrating further potential for achieving the precision required by JUNO’s core oscillation measurements.

Speaker: 赖浩菁 （Haojing Lai) (Shanghai Jiao Tong University)

116 Core-Collapse Supernova Neutrino Monitoring System in JUNO

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20-kiloton liquid scintillator detector with excellent sensitivity to detect neutrinos from the next Core-Collapse Supernova (CCSN). The real-time CCSN monitoring system of JUNO is designed to provide fast and reliable alerts by tracking the increasing event rate of supernova burst neutrinos and pre-supernova neutrinos.

The monitoring framework consists of a prompt monitor at the electronics stage, an online monitor at the data acquisition (DAQ) level, and a multi-messenger monitor based on low-threshold triggers. This configuration ensures second-level alert generation while maintaining full coverage of the Milky Way, with a false-alert rate kept below 1 per month.

Upon detecting an alert, the system will record data in triggerless mode, and a quick analysis is performed to issue fast alerts for a multi-messenger observation of CCSN events. For this purpose, the monitoring system is connected to the SuperNova Early Warning System (SNEWS 2.0).

This talk will present the implementation and current operational status of the CCSN monitoring system, as well as evaluate its alert performance based on simulation studies.

Speaker: Aman Gupta (Institute of High Energy Physics (IHEP), Beijing)

6:00 PM Conference Banquet

Friday, September 4

Plenary: Plenary (Friday AM-1)

117 New Approaches to Precision Neutrino Cross-Section Measurements

The last two decades have witnessed remarkable progress in the measurement of neutrino cross sections relevant to oscillation experiments. At the same time, this growing body of data has exposed significant limitations in our theoretical understanding of neutrino-nucleus interactions and has stimulated the development of new experimental approaches. This effort is particularly timely, as the physics reach of next-generation long-baseline experiments, most notably DUNE and Hyper-Kamiokande, will strongly benefit from a substantial reduction of cross-section uncertainties.
In this talk, I will review some of the emerging strategies for high-precision neutrino cross-section measurements at the GeV scale. These include ancillary hadron-interaction measurements aimed at improving the knowledge of neutrino fluxes, as well as a new generation of short-baseline experiments specifically designed for precision cross-section studies.
Special emphasis will be given to the nuSCOPE proposal, which aims to exploit, for the first time, a monitored and tagged neutrino beam. By providing unprecedented control of the neutrino source in terms of flavor, energy, and flux, this approach brings neutrino beams closer to the level of source characterization routinely achieved with conventional charged-particle beams. It therefore opens the way to a new precision regime in neutrino-nucleus scattering, bringing weak-interaction measurements closer to the level of control traditionally associated with electron scattering, while providing unique access to the axial response of nuclei.

Speaker: Dr Francesco Terranova (CERN)

118 Laser-Driven Compact Muon Source: Production and Optimization for Versatile Applications

Muons, which play a crucial role in both fundamental and applied physics, have traditionally been generated through proton accelerators or from cosmic rays. In this work, we show the first proof of principle experiment for novel muon production with an ultra-short, high-intensity laser device through GeV electron beam bombardment on a lead converter target. The results show that the dominant contributions of muons are attributed to the photo-production/electro-production and a significant yield of muons up to 0.01 μ/e- out of the converter target could be achieved. This laser-driven compact muon source from GeV-level electrons presents an alternative to cosmic-ray and large-scale proton-accelerator-based muon sources thus significantly lowering technical barriers for muon-based research. We further systematically investigate muon production mechanisms. Our analysis addresses critical requirements for both high-energy collimated muon beams and specialized applications such as muon spin rotation/resonance/relaxation research utilizing surface/decay muons. Our simulations derive optimized target configurations to specific application demands and characterize key performance parameters of the generated muon sources. These findings provide foundational guidance for establishing practical muon research capabilities within compact laser laboratories.

Speaker: Feng Zhang (Laser Fusion Research Center, CAEP)

119 Outreach actitivies at IHEP

Outreach actitivies at IHEP

Speaker: Ms Liu Yichun (IHEP)

10:30 AM Coffee Break

Plenary: Plenary (Friday AM-2)

120 Progress of Muonium-Antimuonium Conversion Experiment

Advances in accelerator technology have led to significant
improvements in the quality of muon beams over the past decades.
Investigations of the muon and muonium enable precise measurements of
fundamental constants, as well as searches for new physics beyond the
Standard Model. The spontaneous conversion of muonium to antimuonium is
an interesting charged lepton flavor violation phenomenon and serves as
a tool to constrain the parameter space beyond the Standard Model. The
Muonium-to-Antimuonium Conversion Experiment (MACE) was designed to
utilize a high-intensity muon beam, a Michel electron magnetic
spectrometer, a positron transport system, and a positron detection
system to either discover or constrain this rare process with an
unprecedented precision. This talk will present progress of MACE and the
related areas.

Speaker: Jian Tang (Sun Yat-sen University)

121 TRIDENT Status Updates

TRIDENT Status Updates

Speaker: Hualin Mei

12:30 PM Lunch

WG1 — Machine Learning & Reconstruction for Oscillations

122 Deep Learning for a Deep Detector: Neural Network Reconstruction at Hyper-Kamiokande

NuFact 2026,
Tsung-Dao Lee Institute,
No.1 Lisuo Road, Pudong New District, Shanghai 201210, China
August 31, 2026 to September 5, 2026
—------------------------------------------------------------------------------------------------------
The Hyper-Kamiokande detector represents the next generation of neutrino observatories, following in the lineage of the Kamiokande and Super-Kamiokande experiments. With significantly enhanced sensitivity, Hyper-Kamiokande will support a diverse and ambitious physics program, including searches for proton decay, studies of solar neutrinos under non-standard interactions, and the potential first observation of leptonic CP violation. Designed to contain 260 kilotons of water and equipped with 20,000 photomultiplier tubes of 20 inches, the scale and complexity of Hyper-Kamiokande necessitate the development of advanced event reconstruction algorithms in order to fully exploit the detector performance and achieve the measurements with higher precision.

In this presentation, we explore how next-generation approaches from the field of machine learning — specifically, Deep Neural Networks — can enhance reconstruction performances. Particular emphasis will be placed on the designs of Convolutional Neural Networks and their non-euclidian extension, Graph Neural Networks, which both already demonstrate excellent results on several benchmarks such as particle identification or momentum reconstruction. A section will be devoted to the performance gains obtained by the use of the Transformers architecture as the network backbone, surpassing the current maximum likelihood reconstruction algorithm adapted from Super-Kamiokande.
Erwan Roger Le Blévec
PhD Student at Laboratoire Leprince-Ringuet & ILANCE

Speaker: Erwan Le Blévec (Laboratoire Leprince-Ringuet)

123 Machine Learning in the JUNO Experiment: An Overview

The Jiangmen Underground Neutrino Observatory (JUNO) is a neutrino experiment located in China with a broad physics program. Following nearly a decade of construction, JUNO began physics data-taking on August 26, 2025. The primary goals of the experiment are the determination of the neutrino mass ordering and the high-precision measurement of neutrino oscillation parameters. JUNO's central detector is an acrylic sphere 35.4 meters in diameter filled with 20 kt of liquid scintillator. The detector is equipped with photomultiplier tubes (PMTs) of two types: 17,596 20-inch PMTs and 25,587 3-inch PMTs, which record the intensity and timing of scintillation light.

Due to the detector's large size and complexity, JUNO is expected to benefit from machine learning (ML) techniques in meeting its strict performance requirements. This talk will review various ML developments within the experiment. Specifically, in the MeV regime, I will cover ML models developed for waveform, vertex, and energy reconstruction, alongside selection algorithms for inverse beta decay events. For atmospheric neutrinos, neural network applications to perform particle identification, event directionality, and energy reconstruction will be discussed. Additionally, I will report on JUNO's efforts regarding ML-based muon track reconstruction, which enhances cosmic background veto efficiency. Finally, I will discuss the application of simulation-based inference for detector energy response parameter tuning.

Speaker: Arsenii Gavrikov (TDLI, SJTU)

124 Measurement of neutrino oscillations in JUNO

Jiangmen Underground Neutrino Observatory (JUNO) is a kiloton-scale liquid scintillator detector located in southern China. Its main goals are determination of the neutrino mass ordering (NMO) and high-precision measurement of neutrino oscillation parameters by means of reactor antineutrinos. JUNO started physics data taking in the end of August 2025 and released the world-leading measurement of solar oscillation parameters already after 60 days of data taking. Since then JUNO continues the data taking in order to achieve its scientific goals. This talk will be focused on how the oscillation analysis is performed in JUNO, as well as on its results.

Speaker: Petr Lenskii (Joint Institute for Nuclear Research)

125 First Results from the Search for Muon-Neutrino Disappearance with the ICARUS Detector

After successful operation at LNGS and a major upgrade at CERN, the 760-ton ICARUS T600 detector has been running at Fermilab since 2020, collecting neutrino interactions from the BNB and NuMI beams. In late 2025, ICARUS reached five years of continuous data taking, demonstrating the maturity of large-scale LAr-TPC technology and its relevance for future experiments such as DUNE.

This contribution presents the first ICARUS search for muon-neutrino disappearance in the BNB. Charged-current 1$\mu$1Np events selected from 2022–2023 data are compared to simulations and interpreted, for the first time, within a two-neutrino approximation of the 3+1 sterile-neutrino model, including systematic uncertainties from flux, interaction, and detector effects.

Although currently limited by systematic uncertainties, this first oscillation analysis probes the parameter space suggested by existing $\nu_\mu$ disappearance results and lays the groundwork for future SBN combined analyses with SBND, which will significantly improve sensitivity to sterile-neutrino scenarios.

Speaker: Alessandro Menegolli

WG2 — Collider & High-Energy Neutrinos

126 FASER at the LHC: Collider Neutrinos and Searches for New Physics

The FASER experiment is located 480 m downstream of the ATLAS interaction point at the Large Hadron Collider (LHC), aligned with the beam collision axis. Shielded by approximately 100 meters of rock and concrete, FASER operates in an exceptionally low-background environment that enables unique studies of forward physics. TThe experiment's goals include two complementary physics programs: searches for light, weakly interacting beyond-the-Standard-Model particles and measurements of high-energy collider neutrinos.

Using proton–proton collision data collected during LHC Run 3 at \sqrt{s} 13.6 TeV, FASER has produced exciting physics results in both areas. In neutrino physics, the experiment has opened a new energy regime through the detection and study of TeV-scale neutrinos produced at a particle collider. Recent results include neutrino interaction measurements with both the FASERν emulsion detector and the FASER electronic detector. In parallel, FASER has achieved world-leading sensitivity in searches for light, weakly interacting particles beyond the Standard Model.

In this talk, we will present the latest neutrino results obtained with the FASERν detector and the FASER electronic detector, together with an overview of recent beyond-the-Standard-Model searches and future prospects of the experiment.

Speaker: Umut Kose (ETH Zurich)

127 First Measurement of Muon Neutrinos as a Function of Energy and Rapidity with the FASER experiment

The Forward Search Experiment (FASER) at the CERN Large Hadron Collider (LHC) provides access to TeV-scale neutrinos produced in the far-forward region of proton-proton collisions. Using the electronic detector components of FASER and an integrated luminosity of $186 \pm 4~\mathrm{fb}^{-1}$ collected during LHC Run 3 at $\sqrt{s}=13.6~\mathrm{TeV}$, charged-current muon neutrino interactions are measured in bins of neutrino rapidity and muon charge-over-momentum. The observed event yields are unfolded using a likelihood-based fit including detector efficiencies, migration matrices, and background constraints. After subtraction of the expected backgrounds, $766.8 \pm 29.6$ interaction events are observed. The resulting double-differential distributions probe both the angular and energy structure of the forward neutrino flux and provide sensitivity to neutrino production from light-hadron and charm decays, as well as to TeV-scale neutrino interaction cross sections. These results extend previous collider neutrino measurements by providing the first double-differential characterization of TeV-scale neutrinos produced at the LHC.

Speaker: Wissal Filali (University of Bonn)

128 Latest Results from the SND@LHC Experiment

The SND@LHC detector is a compact, stand-alone experiment designed to measure neutrinos produced at the LHC in a previously unexplored region of pseudorapidity, specifically between 7.2 and 8.6. This region complements those covered by other LHC experiments. The detector is situated 480 meters downstream from IP1 in the unused TI18 tunnel. It is composed of a hybrid system based on an 800 kg target mass of tungsten plates, interleaved with emulsion and electronic trackers, followed downstream by a calorimeter and a muon system. This configuration allows for efficient discrimination among all three neutrino flavors and provides a unique opportunity to investigate heavy-flavor production at the LHC in a kinematic region that is inaccessible to ATLAS, CMS, and LHCb. This region is also particularly significant for future circular colliders and for predicting very high-energy atmospheric neutrinos. Additionally, the detector concept is well-suited for searching for Feebly Interacting Particles by observing signatures of scattering in the detector target. Since 2022, the experiment has collected 309 fb⁻¹ of data with an efficiency of 97%.
Using data from the electronic detectors, interactions with muon neutrinos have been identified, along with solid evidence for interactions with electron neutrinos. In this presentation, we will share results from data collected in 2025, including an analysis of the muon flux, which has greatly enhanced our understanding of the behavior of LHC beams. The reconstruction of emulsion data has now achieved sub-micrometer resolution, and significant progress has been made in vertex finding and electromagnetic shower recognition.

Speaker: Nayana Bangaru

129 The NINJA neutrino experiment at J-PARC

The NINJA experiment in the T2K beam employs nuclear emulsion detectors to study neutrino interactions. A key advantage of nuclear emulsion technology is its extremely high spatial granularity allowing for sub-micron spatial resolution. This feature enables the reconstruction of short particle tracks originating in the vicinity of the neutrino interaction vertex, allowing for detailed characterization of low-energy final-state particles, e.g. protons with a momentum threshold of approximately 200 MeV/c.

The NINJA detector was installed in the B2 floor of the near detector complex of the T2K neutrino experiment and utilizes the neutrino beam produced at J-PARC. It comprises emulsion detectors and a scintillator detector to provide timing information. To date, the experiment has conducted three physics runs (November 2019-February 2020, November 2023-February 2024, and November 2025-March 2026). The first two runs were performed with a 75 kg water target, while the most recent run consisted of a larger 100 kg water target, providing increased statistics.

The capability to detect low-momentum protons makes NINJA particularly well suited to study nuclear effects such as multi-nucleon correlations and final-state interactions, which are critical for reducing systematic uncertainties in neutrino energy reconstruction. In this contribution, an overview of the NINJA experiment will be presented, along with the current status of the data analysis.

Speaker: Mahesh Jakkapu (Ruđer Bošković Institute, Zagreb, Croatia)

WG4 — Muon Physics & Applications

130 Muonium Spectroscopy as a Quantum Sensor for Axion Dark Matter

High-intensity muon beams could enable a muonium-based search for axions through resonant quantum transitions between hyperfine states. Combining theoretical calculations with simulation results, we demonstrate that such a muonium-based experimental approach could complement and tighten constraints on the axion-muon coupling beyond existing limits from the muon g−2 measurement, over the axion mass range of 18–130 µeV. These results establish a new spectroscopic channel in muonium that enables searches for axion and axion-like particle dark matter.

Speaker: Feng FANG (Advanced Energy Science and Technology Guangdong Laboratory)

131 Probing Cosmic Ray Composition and Muon-philic Dark Matter using GeV Muon sources

We propose here a set of new proposals and some preliminary experimental results involving probing and knocking with muons (PKMu). There is a wealth of rich physics to explore with GeV muon beams either from dedicated beam or cosmic source. Examples include but not limited to: muon scattering can occur at large angles, providing evidence of potential muon-philic dark matter or dark mediator candidates; muon-electron scattering can be used to detect new types of bosons associated with charged lepton flavor violation; precise measurements of GeV-scale muon-electron scattering can be employed to probe quantum correlations.

https://arxiv.org/abs/2503.22956 https://arxiv.org/abs/2411.12518https://arxiv.org/abs/2507.23458 https://arxiv.org/abs/2511.08950 https://arxiv.org/abs/2411.12518

Speakers: Qiang Li (Peking University), Qite Li (Peking University)

132 Progress of the MELODY project

Muon station for sciEnce technoLOgy and inDustrY (MELODY) is the first muon source project in China. It aims at both fundamental muon physics and muon applications in various fields. In phase I we will construct a surface muon beam with one muSR spectrometer and one test beam port for technology development and possible muon physics experiment. We also reserve the tunnel for a decay muon beamline and a dedicated negative muon beamline. In this work we present the progress of the project and welcome collaborations from all the world.

Speaker: Yu Bao (IHEP)

133 DREAMuS - Searching for Muon-philic Dark Matter with a GeV Muon Beam at HIAF

We propose DREAMuS (Dark matter REsearch with Advanced Muon Source), a fixed-target experiment at the High-Intensity Heavy-Ion Accelerator Facility (HIAF) in China, designed to search for muon-philic dark-sector particles. DREAMuS uses a GeV-scale muon beam to probe light mediators that preferentially couple to muons and induce lepton-flavor-violating muon-nucleus interactions, followed by invisible decays into dark-sector particles.

The signal is characterized by a single electron candidate with large transverse momentum or large scattering angle, missing momentum. The detector concept has been optimized toward a low-cost scintillator-based design: a segmented lead target is combined with near-target scintillator stations and a multi-layer scintillator-strip barrel to reconstruct and veto muon-related backgrounds, including large-angle scattered muons, muon decays after multiple scattering, and muon-nuclear interactions. The projected sensitivity shows that DREAMuS can probe light muon-philic dark-sector particles over a broad sub-GeV to GeV mass range. A complementary positive-muon beam configuration further improves the low-mass reach through the invisible annihilation channel.

Speaker: 陈翔 (Xiang Chen)

3:40 PM Coffee Break

JOINT WG1+WG3 — Beams for Precision Oscillation Physics

134 First Data with the Upgraded T2K Beam: Validation Using the Near Detector

T2K is a long-baseline experiment measuring neutrino and antineutrino oscillations by observing the disappearance of muon neutrinos, as well as the appearance of electron neutrinos. The ND280 near detector at J-PARC plays a crucial role to minimize the systematic uncertainties related to the neutrino flux and neutrino-nucleus interactions of the un-oscillated neutrino beam. Part of ND280 has recently been upgraded with a new suite of sub-detectors. These new detectors permit analyses with lower tracking thresholds, full angular acceptance and the measurement of kinematics of neutrons produced in neutrino interactions. Alongside this upgrade, the three magnetic horns that select the charge of the decay hadrons produced at the neutrino beamline had their current increased from 250 kA to 320 kA, leading to a purer and more intense (anti-)neutrino flux. This beam upgrade is expected to lead to a ~ 10% increase in the number of events at the peak of the neutrino flux. Before exploiting data collected with the newly installed detectors, a fundamental step is required: the validation of the upgraded neutrino flux. To this end, the original part tracker is used as a benchmark to compare data collected before and after the beam upgrade, using well-understood detector components. This talk will present evidence for the validation of the upgraded beam, showing for the first time data collected with the 320 kA neutrino flux.

Speaker: Jean-Baptiste Plancon

135 The Synergistic Role of JUNO in Global Neutrino Oscillation Measurements with NOvA and T2K

We study the impact of combining the present NO$\nu$A and T2K data with simulated data from the JUNO experiment on the determination of the leptonic CP phase and the neutrino mass hierarchy. The current NO$\nu$A data exhibit a hierarchy--$\delta_{\mathrm{CP}}$ degeneracy, admitting both normal hierarchy (NH) with $\delta_{\mathrm{CP}} \in [0,180^\circ]$, and inverted hierarchy (IH) with $\delta_{\mathrm{CP}} \in [180^\circ,360^\circ]$ solutions at comparable significance, while T2K prefers $\delta_{\mathrm{CP}}\simeq 270^\circ$ for both hierarchies, leading to a $2\sigma$ tension between the two experiments for normal hierarchy. Using detailed GLoBES simulations, we show that future JUNO data with excellent hierarchy sensitivity can lift the hierarchy--$\delta_{\mathrm{CP}}$ degeneracy in NO$\nu$A and strengthen the hierarchy reach of T2K despite having no $\delta_{\mathrm{CP}}$ sensitivity. Allowing the hierarchy to be a free parameter in the fit, if the true ordering is IH, JUNO aligns the NO$\nu$A and T2K allowed regions and resolves their present tension; if NH is true, the tension continues to persist. We also show that JUNO’s precise measurement of $|\Delta_{31}|$ leads to improved constraints on $\sin^2\theta_{23}$ and $\delta_{\mathrm{CP}}~$ for normal mass hierarchy in NO$\nu$A even though JUNO itself is insensitive to these parameters. Finally, updated solar-parameter measurements from JUNO’s first data release further enhance the combined precision. Our results demonstrate that JUNO plays a crucial synergistic role in the global neutrino-oscillation programme, enabling a more robust determination of the mass ordering and improving the sensitivity to the CP phase when combined with long-baseline data.

Speaker: Aman Gupta (Institute of High Energy Physics (IHEP), Beijing)

136 Carving a Neutrino Factory: A Multi-Disciplinary Conceptual Design Methodology for ESSnuSB

The ESSnuSB project aims at searching the matter anti-matter asymmetry at 5 σ significance level, in more than 70% of the lepton Dirac δCP violating phase range, and measuring the phase value with precision. Its first phase, the ESSnuSB, investigated the upgrade of the European Spallation Source to deliver the intense neutrino beam toward a far detector hosted within the Zinkgruvan mine, Sweden. Its extension phase, ESSnuSBplus, is aiming at neutrino-nucleus cross-section measurements at the low neutrino energies. ESSnSB experiment will benefit from the very high intensity of the European Spallation Source 5 MW linac in Lund (Sweden) allowing the installation of the far neutrino detector at the second oscillation maximum.

However, several technological challenges must be studied before the design of the ESSnSB experiment. In particular, the design of the accumulator ring and the Target-Station producing the neutrino super-beam from the proton linac beam is one of the highest priorities at this phase of the project. Moreover, the facility combines civil engineering works at an operating accelerator complex, subject to coupled radiological, geotechnical and operational constraints. This contribution presents the multi-disciplinary design methodology developed for ESSnuSB, in particular, the linac-to-accumulator transfer line, the accumulator ring, the ring-to-target transfer line and the staged target-station deployment, all integrated within the operating ESS site.

We will report on the ongoing design and civil engineering efforts for the ESSnuSB project that lies within the ESS site.

Speaker: Dr Ioannis Christodoulou (European Spallation Source)

137 Demonstration of Two Dimensional Muon Profile Measurements by Electron Multiplier Tubes in the T2K Experiment

The key to unraveling the mystery of the matter-dominated universe is believed to lie in CP violation in the lepton sector. The T2K experiment is a long-baseline neutrino oscillation experiment in which neutrinos produced by the J-PARC proton accelerator are detected at Super-Kamiokande, located 295 km away.

MUMON is a detector located about 100 meters downstream of the neutrino production target. It uses Silicon and Ionization Chamber detectors to measure muons, which are byproducts of neutrino production, and thereby monitors the proton and neutrino beam profiles in real time.
In preparation for the Hyper-Kamiokande (HK) experiment, scheduled to begin in 2028, efforts are underway to increase the proton beam power to 1.3 MW. Under these conditions, the silicon detectors are expected to suffer severe radiation damage and will require replacement as frequently as once per month.
This issue will pose a challenge for stable long-term operation.

To address this issue, we are conducting R&D on Electron Multiplier Tubes (EMTs) as radiation-tolerant sensors. Past beam tests have confirmed that EMTs have sufficient radiation tolerance and linearity.
In this presentation, I report the accuracy of muon beam profile measurements using EMTs arranged in plus and star-shaped configuration within MUMON. Also, I will show the observed signal instability and its status.

Speaker: Sota Kobayashi (Tohoku University)

WG2 — New Facilities for Cross-Section Measurements

138 High precision neutrino interaction measurements with the nuSCOPE experiment

The poor knowledge of neutrino cross sections at the GeV scale is projected to be responsible for some of the leading sources of uncertainty in next-generation oscillation experiments. Building on the ideas and R&D from ENUBET and NuTAG, we present a proposal for the nuSCOPE experiment (see arXiv:2503.21589). nuSCOPE is a high-precision, short-baseline neutrino experiment at CERN that employs neutrino monitoring and tagging. This allows for an exceptionally well controlled muon and electron neutrino flux, with the extraordinary capacity to reconstruct neutrino energy on an event-by-event basis. This opens up the possibility for a wealth of cross-section measurements usually reserved only for electron-scattering experiments. In this talk we show highlights of projected measurements, incorporating a realistic detector simulation of both liquid argon and water Cherenkov detectors. These results demonstrate the experiment's unique ability to directly measure aspects of neutrino interaction physics responsible for dominant sources of systematic uncertainty for the upcoming DUNE and Hyper-K experiments, but also to perform dedicated measurements of nuclear effects.

Speaker: Leon Halić (Ruđer Bošković Institute)

139 A Narrow-Band Neutrino Beam from HIAF for Precision Neutrino-Nucleus Cross-Section Measurements

As next-generation long-baseline experiments DUNE and Hyper-Kamiokande enter a systematics-dominated era, neutrino-nucleus cross-section uncertainties—particularly for antineutrinos in the 0.3–2.5 GeV range—have become the leading limitation on $\delta_{CP}$ extraction. We present a novel narrow-band neutrino beam produced by instrumenting the High Energy Fragment Separator (HFRS) at China's HIAF as a momentum-selecting pion decay channel. The HFRS first dipole selects pions with $\Delta p/p \approx \pm 2\%$, yielding a neutrino energy spread of 4–5% FWHM—one order of magnitude narrower than conventional horn-focused beams—with wrong-sign and intrinsic $\nu_e$ contamination below 1%. A distinctive feature is the use of $^{16}$O$^{8+}$ primary ions, which produce nearly symmetric $\pi^+$ and $\pi^-$ yields, enabling $\nu_\mu$ and $\bar{\nu}_\mu$ beams of comparable purity and statistics—a capability absent at existing facilities. G4Beamline simulations show a flux-shape uncertainty of 1% and a path to flux normalisation below 2% via in situ calibration. A 500-ton tracking calorimeter at 50 m would collect more than $10^4$ CC events with a 3-year run, enabling differential cross-section measurements with sub-percent statistical precision.

Speaker: 徐宇 (Yu Xu) (先进能源科学与技术广东省实验室)

140 Electron scattering for neutrino physics with e4nu

The extraction of oscillation parameters from next-generation neutrino experiments such as DUNE and Hyper-K will rely on precise estimation of the properties of the incoming neutrino. The relationship between reconstructed and true neutrino energies depends critically on accurate models of neutrino-nucleus interactions, for which uncertainties in nuclear structure and reaction mechanisms are expected to become leading systematic limitations.

Electron scattering provides a powerful complementary probe of these same nuclear dynamics at energies relevant for neutrino experiments. Unlike neutrino beams, electron beams can be delivered at fixed energies and high intensities, enabling high-statistics measurements with well-controlled kinematics. The Electrons for Neutrinos (e4nu) collaboration uses data from electron scattering experiments, including CLAS and CLAS12 at Jefferson Lab, to test and constrain the underlying models used used in neutrino event generators, exploiting the close connection between electron- and neutrino-nucleus scattering.

In this talk, we will present the e4nu research program and recent results from the CLAS12 analysis campaign. These include novel inclusive and semi-exclusive electron scattering on various targets, including argon. We will discuss how these measurements provide stringent benchmarks for interaction models and how electron-scattering data can help reduce nuclear-model uncertainties in future neutrino oscillation measurements.

Speaker: Pablo Barham Alzás (Tel Aviv University)

Saturday, September 5

Plenary: Work Package Summaries (WG1-WG3)

141 WG1 - Neutrino Oscillations

142 WG2 - Neutrino Interactions

143 WG3 - Accelerators

10:30 AM Coffee Break

Plenary: Work Package Summaries (WG4-WG7)

144 WG4 - Muon Physics

145 WG5 - Neutrinos Beyond PMNS

146 WG6 : Detectors

147 WG7 : Inclusion, Diversity, Equity, Education and Outreach

Closing