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ANTARES Collaboration(Albert, A. et al), Alves, S., Calvo, D., Carretero, V., Gozzini, R., Hernandez-Rey, J. J., et al. (2026). Deep learning framework for enhanced neutrino reconstruction of single-line events in the ANTARES telescope. Mach. Learn.-Sci. Technol., 7(3), 035004–27pp.
Abstract: We present the N-fit algorithm designed to improve the reconstruction of neutrino events detected by a single line of the ANTARES underwater telescope, usually associated with low energy neutrino events (similar to 100 GeV). N-Fit is a neural network model that relies on deep learning and combines several advanced techniques in machine learning-deep convolutional layers, mixture density output layers, and transfer learning (TL). This framework divides the reconstruction process into two dedicated branches for each neutrino event topology-tracks and showers-composed of sub-models for spatial estimation-direction and position-and energy inference, which later on are combined for event classification. Regarding the direction of single-line (SL) events, the N-Fit algorithm significantly refines the estimation of the zenithal angle, and delivers reliable azimuthal angle predictions that were previously unattainable with traditional chi 2-fit methods. Improving on energy estimation of SL events is a tall order; N-Fit benefits from TL to efficiently integrate key characteristics, such as the estimation of the closest distance from the event to the detector. N-Fit also takes advantage from TL in event topology classification by freezing convolutional layers of the pretrained branches. Tests on Monte Carlo simulations and data demonstrate a significant reduction in mean and median absolute errors across all reconstructed parameters. The improvements achieved by N-Fit highlight its potential for advancing multimessenger astrophysics and enhancing our ability to probe fundamental physics beyond the Standard Model using SL events from ANTARES data.
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Acerbi, F. et al, Cervera Villanueva, A., Garcia-Peris, M. A., Martin-Albo, J., Querol, M., Rocabado, J., et al. (2026). Cryogenic characterization of FBK NUV-HD-Cryo 3T SiPM sensors for the DUNE photon detection system. J. Instrum., 21(2), P02047–19pp.
Abstract: The Deep Underground Neutrino Experiment (DUNE) is a long-baseline neutrino experiment based in the U.S.A. and composed of a Near Detector (ND) complex at Fermi National Laboratory (FNAL), and a Far Detector (FD) complex located at the Sanford Underground Research Facility (SURF) similar to 1300 km distant. DUNE will study neutrino oscillations looking for unresolved issues of the Standard Model of particle physics (SM) such as CP violation in the leptonic sector, neutrino mass ordering and others, starting from the early 2030s. The FD, with a mass of similar to 17 kt, that will exploit both ionization and scintillation signals to detect neutrino interactions with Argon. Scintillating photons in LAr will be detected by the photon detection system (PDS) based on light collectors coupled to Silicon Photomultipliers (SiPMs). During a test campaign, different laboratories of the collaboration performed an investigation of the best SiPM candidates that fulfill the DUNE FD requirements. We identified two models of SiPM, produced by Hamamatsu Photonics K.K. (HPK) and Fondazione Bruno Kessler (FBK), respectively. In this paper, we focus on the FBK selected model showing its main features. We will describe the characterization protocol, the results at both room and cryogenic temperatures and the photon detection efficiency measurements.
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LHCb Collaboration(Aaij, R. et al), Fernandez Casani, A., Jaimes Elles, S. J., Jashal, B. K., Libralon, S., Lucio Martinez, M., et al. (2026). Measurement of charged-hadron distributions in heavy-flavor jets in proton-proton collisions at √s=13 TeV. J. High Energy Phys., 04, 029–36pp.
Abstract: Charged-hadron distributions in heavy-flavor jets are measured in proton-proton collisions at a center-of-mass energy of root s = 13TeV collected by the LHCb experiment. Distributions of the longitudinal momentum fraction, transverse momentum, and radial profile of charged hadrons are measured separately in beauty and charm jets. The distributions are compared to those previously measured by the LHCb collaboration in jets produced back-to-back with a Z boson, which in the forward region are primarily light-quark-initiated, to compare the hadronization mechanisms of heavy and light quarks. The observed differences between the heavy- and light-jet distributions are consistent with the heavy-quark dynamics expected to arise from the dead-cone effect, as well as with a hard fragmentation of the heavy-flavor hadron as previously measured in single-hadron fragmentation functions. This measurement provides additional constraints for the extraction of collinear and transverse-momentum-dependent heavy-flavor fragmentation functions and offers another approach to probing the mechanisms that govern heavy-flavor hadronization.
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Antusch, S., Levy, M., & Centelles Chulia, S. (2026). Gravity-assisted neutrino masses. Phys. Lett. B, 876, 140410–6pp.
Abstract: Gravity is generally expected to violate global symmetries, including lepton number. However, neutrino masses from the Planck-suppressed Weinberg operator are typically too small to account for oscillation data. We propose a new model-building approach to low-scale neutrino mass generation, in which an intermediate spontaneous symmetry-breaking scale generates masses and mixings in the heavy neutral lepton (HNL) sector, while leaving an unbroken residual symmetry Gres that forbids light-neutrino masses. The observed light-neutrino masses then arise because gravity breaks Gres via Planck-suppressed operators, inducing the small lepton-number violation required in low-scale seesaw constructions. The HNLs form pseudo-Dirac pairs, with masses potentially within reach of future colliders and complementary tests in precision searches such as charged lepton flavour violation (cLFV). As an illustration, we present a representative realisation of this class of models and show that, for O(1) operator coefficients, it predicts a region in the (MR, Theta 2)-plane that can be testable via displaced-vertex searches at the High-Luminosity (HL-)LHC and the FCC-ee.
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Domingo-Pardo, C., Lederer-Woods, C., & Mengoni, A. (2026). Constraining r-process nucleosynthesis via enhanced accuracy neutron-capture experiments. Eur. Phys. J. A, 62(4), 83–10pp.
Abstract: The isotopic abundances of r-process elements in the solar system are traditionally derived as residuals from the subtraction of s-process contributions from total solar abundances. However, the uncertainties in s-process nucleosynthesis – particularly those arising from Maxwellian Averaged Cross Sections (MACS) – propagate directly into the r-process residuals, affecting their reliability. Building upon the seminal work of Goriely (A&A 342:881-891, 1999), who introduced a multi-event s-process model to quantify these uncertainties, we revisit the problem using a simplified yet effective approach. By assuming that the relative uncertainty in s-process isotopic abundances scales linearly with the MACS uncertainties from data libraries (KADoNiS), we identify a subset of isotopes for which the r-process residuals remain significantly uncertain. Using updated solar abundances (Lodders in Space Sci Rev 221:23, 2025) and s-process contributions from Bisterzo et al. (ApJ 787:10, 2014), we present a short list of isotopes that are prime candidates for improved (n,gamma) measurements at CERN nTOF in the near future. Our analysis provides a practical framework for prioritizing future experimental efforts that will profit from upgrades and enhancements of the nTOF facility. It also highlights the need to revisit key neutron-capture cross sections to refine our understanding of the r-process isotopic abundance pattern, commonly used as a benchmark in stellar models of explosive nucleosynthesis.
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