Nuclear and High Energy Physics, Astronomy and Astrophysics, Instrumentation
392
Scopus Publications
Scopus Publications
Inclusive Search for Anomalous Single-Photon Production in MicroBooNE P. Abratenko, D. Andrade Aldana, L. Arellano, J. Asaadi, A. Ashkenazi, et al. Physical Review Letters, 2026 We present an inclusive search for anomalous production of single-photon events from neutrino interactions in the MicroBooNE experiment. The search and its signal definition are motivated by the previous observation of a low-energy excess of electromagnetic shower events from the MiniBooNE experiment. We use the Wire-Cell reconstruction framework to select a sample of inclusive single-photon final-state interactions with a final efficiency and purity of 7.0% and 40.2%, respectively. We leverage simultaneous measurements of sidebands of charged current ν μ interactions and neutral current interactions producing π 0 mesons to constrain signal and background predictions and reduce uncertainties. We perform a blind analysis using a dataset collected from February 2016 to July 2018, corresponding to an exposure of 6.34 × 10 20 protons on target from the Booster Neutrino Beam at Fermilab. In the full signal region, we observe agreement between the data and the prediction, with a goodness-of-fit p value of 0.11. We then isolate a subsample of these events containing no visible protons, and observe 93 ± 22 ( stat ) ± 35 ( syst ) data events above prediction, corresponding to just above 2 σ local significance, concentrated at shower energies below 600 MeV.
Characterization of argon recoils at the keV scale with ReD and ReD+ L. Pandola, P. Agnes, I. Ahmad, S. Albergo, I. Albuquerque, et al. Journal of Instrumentation, 2026 The ReD experiment measured the ionization yield Q y of argon for nuclear recoils in the 2–10 keV range using a dual-phase Time Projection Chamber irradiated with neutrons from a 252 Cf fission source. The measurement extends coverage below 7 keV, confirms consistency with previous data above 7 keV, and indicates a higher Q y at lower energies. These results are relevant for argon-based experiments searching for dark matter in the form of low-mass Weakly Interacting Massive Particles, which are very sensitive to the modeling of the detector response in this energy range.
First Search for Dark Sector e+e- Explanations of the Mini Boo NE Anomaly at Micro Boo NE A. M. Abdullahi, P. Abratenko, D. Andrade Aldana, L. Arellano, J. Asaadi, et al. Physical Review Letters, 2026 We present MicroBooNE’s first search for dark sector e + e − explanations of the long-standing MiniBooNE anomaly. The MiniBooNE anomaly has garnered significant attention over the past 20 years including previous MicroBooNE investigations into both anomalous electron and photon excesses, but its origin still remains unclear. In this Letter, we provide the first direct test of dark sector models in which dark neutrinos, produced through neutrino-induced scattering, decay into missing energy and visible e + e − pairs comprising the MiniBooNE anomaly. Many such models have recently gained traction as a viable solution to the anomaly while evading past bounds. Using an exposure of 6.87 × 10 20 protons-on-target in the Booster Neutrino Beam, we implement a selection targeting forward-going, coherently produced e + e − events. After unblinding, we observe 95 events, which we compare with the constrained background-only prediction of 69.7 ± 17.3 . This analysis sets the world’s first direct limits on these dark sector models and, at the 95% confidence level, excludes the entirety of the single dark neutrino and majority of the dual dark neutrino, parameter space that is viable as a solution to the MiniBooNE anomaly.
Characterization of the ionization response of argon to nuclear recoils at the keV scale with the ReD experiment P. Agnes, I. Ahmad, S. Albergo, I. Albuquerque, M. Atzori Corona, et al. European Physical Journal C, 2026 In the recent years, argon-based experiments looking for Dark Matter in the Universe have explored the non-standard scenario in which Dark Matter is made by low-mass Weakly Interacting Massive Particles, of mass in the range of 1–10 GeV instead of the canonical hundreds of GeV. Detecting such particles is challenging, as their expected signatures are nuclear recoils with energies below 10 keV, observable solely via ionization. This necessitates a precise understanding of the detector response in this energy regime, which remains incomplete for argon. To address this, the ReD experiment was developed within the framework of the DarkSide-20k Collaboration to produce and characterize few-keV nuclear recoils. A compact dual-phase argon Time Projection Chamber (TPC) was irradiated with neutrons from a $$^{252}$$ 252 Cf source, to produce Ar recoils in the energy range of interest via (n,n’) elastic scattering. A downstream spectrometer composed of 18 plastic scintillators detected the neutrons scattered off Ar nuclei, enabling recoil energy reconstruction via two-body kinematics. The ionization yield $$Q_{y}$$ Q y of argon, defined as the number of electrons produced per unit energy deposit, was measured in a model-independent way between 2 and 10 keV. These measurements extend direct experimental coverage well below the previous limit of approximately 7 keV. The results are consistent with existing data above 7 keV, while they indicate a higher $$Q_{y}$$ Q y at lower energies.
Operation of a Modular 3D-Pixelated Liquid Argon Time-Projection Chamber in a Neutrino Beam S. Abbaslu, A. Abed Abud, R. Acciarri, L. P. Accorsi, M. A. Acero, et al. Instruments, 2026 The 2x2 Demonstrator, a prototype for the Deep Underground Neutrino Experiment (DUNE) liquid argon (LAr) Near Detector, was exposed to the Neutrinos from the Main Injector (NuMI) neutrino beam at Fermi National Accelerator Laboratory (Fermilab). This detector is a prototype of a new modular design for a liquid argon time-projection chamber (LArTPC), comprising a two-by-two array of four modules, each further segmented into two optically isolated LArTPCs. The 2x2 Demonstrator features a number of pioneering technologies, including a low-profile resistive field shell to establish drift fields, native 3D ionization pixelated imaging, and a high-coverage dielectric light readout system. The 2.4-tonne active mass detector is flanked upstream and downstream by supplemental solid-scintillator tracking planes, repurposed from the MINERvA experiment, which track ionizing particles exiting the argon volume. The antineutrino beam data collected by the detector over a 4.5 day period in 2024 include over 30,000 neutrino interactions in the LAr active volume—the first neutrino interactions reported by a DUNE detector prototype. During its physics-quality run, the 2x2 Demonstrator operated at a nominal drift field of 500 V/cm and maintained good LAr purity, with a stable electron lifetime of approximately 1.25 ms. This paper describes the detector and supporting systems, summarizes the installation and commissioning, and presents the initial validation of collected NuMI beam and off-beam self-triggers. In addition, it highlights observed interactions in the detector volume, including candidate muon antineutrino events.
Measurement of single charged pion production in charged-current νμ-Ar interactions with the MicroBooNE detector P. Abratenko, D. Andrade Aldana, L. Arellano, J. Asaadi, A. Ashkenazi, et al. Physical Review D, 2026 We present flux-integrated charged-current ν μ cross-section measurements on argon for final states containing exactly one π ± and no other hadrons except nucleons. The analysis uses data from the MicroBooNE experiment in the Booster Neutrino Beam, corresponding to 1.11 × 10 21 protons on target. Total and single-differential cross-section measurements are provided within a phase space restricted to muon momenta above 150 MeV, pion momenta above 100 MeV, and muon-pion opening angles smaller than 2.65 rad. Differential cross sections are reported with respect to the scattering angles of the muon and pion relative to the beam direction, their momenta, and their combined opening angle. The differential cross section with respect to muon momentum is based on a subset of selected events with the muon track fully contained in the detector, whereas the cross section with respect to pion momentum is based on a subset of selected events rich in pions that have not hadronically scattered on the argon before coming to rest. The latter has not been measured on argon before. The total cross section is measured as ( 3.75 ± 0.07 ( stat ) ± 0.80 ( syst ) ) × 10 − 38 cm 2 / Ar at a mean energy of approximately 0.8 GeV. Comparisons of the measured cross sections with predictions from multiple neutrino-nucleus interaction generators show good overall agreement, except at very forward muon angles.
Multi-Detector Analyses for CCSN Neutrino Detection Meriem Bendahman, Isabel Goos, Joao Coelho, Matteo Bugli, Alexis Coleiro, et al. Springer Proceedings in Physics, 2026 Core-collapse supernovae (CCSNe) represent significant astronomical occurrences that offer essential insights into galaxy dynamics. The temporal pattern of neutrinos during these events serves as a distinctive and valuable information source, shedding light on collapsing star mechanisms and particle behaviors in densely packed environments. Despite the rarity of nearby supernovae, one observation of supernova neutrinos has been recorded to date. To optimize our understanding during the next galactic CCSN, it is crucial to amalgamate real-time observations from multiple neutrino experiments and promptly convey the results to optical telescopes. However, pinpointing the CCSN poses a substantial challenge, requiring the separation of localization information from signatures associated with supernova progenitor properties or neutrino physics. Existing CCSN distance measurement algorithms assume accurate predictions of neutrino properties by the Standard Model. This contribution introduces an approach to rapidly and effectively extract and distinguish information about CCSN and neutrino physics. We demonstrate the robustness of this approach against potential biases in CCSN measurements due to new physics effects, leveraging the diverse capabilities of next-generation neutrino detectors.
First Measurement of Charged-Current Muon-Neutrino-Induced K+ Production on Argon Using the MicroBooNE Detector P. Abratenko, D. Andrade Aldana, L. Arellano, J. Asaadi, A. Ashkenazi, et al. Physical Review Letters, 2025 The MicroBooNE experiment is an 85 tonne active mass liquid argon time projection chamber neutrino detector exposed to the on-axis Booster Neutrino Beam at Fermilab. One of MicroBooNE’s physics goals is the precise measurement of neutrino interactions on argon in the 1 GeV energy regime. Building on the capabilities of the MicroBooNE detector, this analysis identifies K + mesons, a key signature for the study of strange particle production in neutrino interactions. This measurement is furthermore valuable for background estimation for future nucleon decay searches and for improved reconstruction and particle identification capabilities in experiments such as the Deep Underground Neutrino Experiment. In this Letter, we present the first-ever measurement of a flux-integrated cross section for charged-current muon neutrino induced K + production on argon nuclei, determined to be 7.93 ± 3.22 ( stat ) ± 2.83 ( syst ) × 10 − 42 cm 2 / nucleon based on an analysis of 6.88 × 10 20 protons on target. This result was found to be consistent with model predictions from different neutrino event generators within the reported uncertainties.
Search for light sterile neutrinos with two neutrino beams at MicroBooNE P. Abratenko, D. Andrade Aldana, L. Arellano, J. Asaadi, A. Ashkenazi, et al. Nature, 2025 The existence of three distinct neutrino flavours, ν e , ν μ and ν τ , is a central tenet of the Standard Model of particle physics 1,2 . Quantum-mechanical interference can allow a neutrino of one initial flavour to be detected sometime later as a different flavour, a process called neutrino oscillation. Several anomalous observations inconsistent with this three-flavour picture have motivated the hypothesis that an additional neutrino state exists, which does not interact directly with matter, termed as ‘sterile’ neutrino, ν s (refs. 3–9 ). This includes anomalous observations from the Liquid Scintillator Neutrino Detector (LSND) 3 experiment and Mini-Booster Neutrino Experiment (MiniBooNE) 4,5 , consistent with ν μ → ν e transitions at a distance inconsistent with the three-neutrino picture. Here we use data obtained from the MicroBooNE liquid-argon time projection chamber 10 in two accelerator neutrino beams to exclude the single light sterile neutrino interpretation of the LSND and MiniBooNE anomalies at the 95% confidence level (CL). Moreover, we rule out a notable portion of the parameter space that could explain the gallium anomaly 6–8 . This is one of the first measurements to use two accelerator neutrino beams to break a degeneracy between ν e appearance and disappearance, which would otherwise weaken the sensitivity to the sterile neutrino hypothesis. We find no evidence for either ν μ → ν e flavour transitions or ν e disappearance that would indicate non-standard flavour oscillations. Our results indicate that previous anomalous observations consistent with ν μ → ν e transitions cannot be explained by introducing a single sterile neutrino state.
Characterization of low-energy argon recoils with the ReD experiment Proceedings of Science, 2024
The study of neutrinos and antineutrinos from astrophysical sources by Borexino Proceedings of Science, 2024
Directionality measurement of CNO neutrinos with Borexino detector Proceedings of Science, 2024
Combined directional and spectral analysis of solar neutrinos from Carbon-Nitrogen-Oxygen fusion cycle with Borexino Experiment Proceedings of Science, 2024
Searching for solar KDAR with DUNE A. Abed Abud, B. Abi, R. Acciarri, M.A. Acero, M.R. Adames, et al. Journal of Cosmology and Astroparticle Physics, 2021
Dark Matter Search Application to Medical Physics: The 3D? Project Proceedings of Science, 2021
The Low Polonium Field of Borexino and its significance for the CNO neutrino detection Proceedings of the 55th Rencontres De Moriond 2021 Electroweak Interactions and Unified Theories Ew 2021, 2021
First detection of CNO neutrinos with Borexino Proceedings of the 55th Rencontres De Moriond 2021 Electroweak Interactions and Unified Theories Ew 2021, 2021
The recent results of the solar neutrino measurement in Borexino Proceedings of the 46th Rencontres De Moriond 2011 Electroweak Interactions and Unified Theories Ew 2011, 2020
DarkSide status and prospects S. Sanfilippo, P. Agnes, I. Albuquerque, T. Alexander, A. Alton, et al. Nuovo Cimento Della Societa Italiana Di Fisica C, 2019
DarkSide-50 results and the future liquid argon dark matter program Proceedings of Science, 2019
Results from borexino at lngs Stefano Davini, M. Agostini, I. Drachnev, S. Marcocci, G. Bellini, et al. Proceedings of the 17th Lomonosov Conference on Elementary Particle Physics Particle Physics at the Year of Light 2015, 2017
Direct dark matter search Anselmo Meregaglia, Davide Franco, Marcello Messina, Claudio Montanari, Francesco Pietropaolo Advances in High Energy Physics, 2015
Precision muon reconstruction in Double Chooz Y. Abe, J.C. dos Anjos, J.C. Barriere, E. Baussan, I. Bekman, et al. Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment, 2014
Recent Borexino results and prospects for the near future Proceedings of the 49th Rencontres De Moriond 2014 Electroweak Interactions and Unified Theories Ew 2014, 2014
Precision measurement of the beryllium-7 line with the Borexino detector Proceedings of the 48th Rencontres De Moriond 2013 Electroweak Interactions and Unified Theories Ew 2013, 2013
Low energy neutrinos G. Ranucci, G. Bellini, J. Benziger, D. Bick, G. Bonfini, et al. Proceedings 33rd International Symposium on Physics in Collision Pic 2013, 2013
Measurement of CNGS muon neutrino speed with Borexino P. Alvarez Sanchez, R. Barzaghi, G. Bellini, J. Benziger, B. Betti, et al. Physics Letters Section B Nuclear Elementary Particle and High Energy Physics, 2012
Measurement of 7Be and 8B solar neutrinos with Borexino Frascati Physics Series, 2010
Observation of geo-neutrinos G. Bellini, J. Benziger, S. Bonetti, M. Buizza Avanzini, B. Caccianiga, et al. Physics Letters Section B Nuclear Elementary Particle and High Energy Physics, 2010
CNO and pep neutrino spectroscopy in borexino: Measurement of the cosmogenic 11c background with the counting test facility Neutrino 2006 Proceedings of the 22nd International Conference on Neutrino Physics and Astrophysics, 2006
