Montesinos, V., Ikeno, N., Oset, E., Albaladejo, M., Nieves, J., & Tolos, L. (2025). On the determination of the D meson width in the nuclear medium with the transparency ratio. Phys. Lett. B, 860, 139172–6pp.
Abstract: We have studied the feasibility of the experimental determination of the width of a D meson in a nuclear medium by using the method of the nuclear transparency. The cross section for inclusive production of a D+ in different nuclei is evaluated, taking care of the D+ absorption in the nucleus, or equivalently, the survival probability of the D+ in its way out of the nucleus from the point of production. We use present values of the in medium width of D mesons and calculate ratios of the cross sections for different nuclei to the 12 C nucleus as reference. We find ratios of the order of 0.6 for heavy nuclei, a large deviation from unity, which indicates that the method proposed is adequate to measure this relevant magnitude, so far only known theoretically.
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Batra, A., Bharadwaj, P., Mandal, S., Srivastava, R., & Valle, J. W. F. (2025). Large lepton number violation at colliders: Predictions from the minimal linear seesaw mechanism. Phys. Lett. B, 860, 139204–11pp.
Abstract: Small neutrino masses can be sourced by a tiny vacuum expectation value of a leptophilic Higgs doublet, and mediated by Quasi-Dirac heavy neutrinos. In such simplest linear seesaw picture the neutrino mass mediators can be accessible to colliders. We describe novel charged Higgs and heavy neutrino production mechanisms that can be sizeable at + – , -, , or muon colliders and discuss some of the associated signatures. The oscillation length of the heavy neutrino mediators is directly related to the light neutrino mass ordering. Moreover, lepton number violation can be large despite the smallness of neutrino masses, and may shed light on the Majorana nature of neutrinos and the significance of basic symmetries in weak interaction.
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Romeo, B., Stramaccioni, D., Menéndez, J., & Valiente-Dobón, J. J. (2025). A pathway to unveiling neutrinoless ββ decay nuclear matrix elements via γγ decay. Phys. Lett. B, 860, 139186–7pp.
Abstract: We investigate the experimental feasibility of detecting second-order double-magnetic dipole ( – 1 1) decays from double isobaric analog states (DIAS), which have recently been found to be strongly correlated with the nuclear matrix elements of neutrinoless decay. Using the nuclear shell model, we compute theoretical branching ratios for -11 decays and compare them with other competing processes, such as single- decay and proton emission, which represent the dominant decay channels. We also estimate the potential competition from internal conversion and internal pair creation, which can influence the decay dynamics. Additionally, we propose an experimental strategy based on using LaBr3 scintillators to identify -11 transitions from the DIAS amidst the background of the competing processes. Our approach emphasizes the challenges of isolating the rare -11 decay and suggests ways to enhance the experimental detection sensitivity. Our simulations suggest that it may be possible to access experimentally -11 decays from DIAS, shedding light on the neutrinoless decay nuclear matrix elements.
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ATLAS Collaboration(Aad, G. et al), Aikot, A., Amos, K. R., Bouchhar, N., Cabrera Urban, S., Cantero, J., et al. (2025). Combination of searches for singly and doubly charged Higgs bosons pvroduced via vector-boson fusion in proton-proton collisions at √s=13 TeV with the ATLAS detector. Phys. Lett. B, 860, 139137–21pp.
Abstract: A combination of searches for singly and doubly charged Higgs bosons, H-+/- and H-+/-+/-, produced via vector-boson fusion is performed using 140 fb(-1) of proton-proton collisions at a centre-of-mass energy of 13 TeV, collected with the ATLAS detector during Run 2 of the Large Hadron Collider. Searches targeting decays to massive vector bosons in leptonic final states (electrons or muons) are considered. New constraints are reported on the production cross section times branching fraction for charged Higgs boson masses between 200 GeV and 3000 GeV. The results are interpreted in the context of the Georgi-Machacek model for which the most stringent constraints to date are set for the masses considered in the combination.
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Cherchiglia, A. L., Dias, A. G., Leite, J., & Nishi, C. C. (2025). Seesaw limit of the Nelson-Barr mechanism. Phys. Lett. B, 860, 139222–7pp.
Abstract: We investigate how the solution to the strong CP problem and the explanation for the observed fermion mass hierarchies can be intrinsically related. Specifically, we explore the Nelson-Barr mechanism and identify its “seesaw limit”, where light quark masses are suppressed by large CP-violating terms. Upon adding three (two) vector-like quarks that mix with the down-type (up-type) quark sector of the Standard Model, we demonstrate how the lack of CP violation in the strong sector and the observed quark mass hierarchy can be simultaneously achieved.
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