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Cordero-Carrion, I., Hirsch, M., & Vicente, A. (2020). General parametrization of Majorana neutrino mass models. Phys. Rev. D, 101(7), 075032–25pp.
Abstract: We discuss a general formula which allows to automatically reproduce experimental data for Majorana neutrino mass models, while keeping the complete set of the remaining model parameters free for general scans, as necessary in order to provide reliable predictions for observables outside the neutrino sector. We provide a proof of this master parametrization and show how to apply it for several well-known neutrino mass models from the literature. We also discuss a list of special cases, in which the Yukawa couplings have to fulfill some particular additional conditions.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., et al. (2020). Measurement of |V-cb| with B-s(0) -> D-s(()*()-) mu(+)nu(mu) decays. Phys. Rev. D, 101(7), 072004–25pp.
Abstract: The element vertical bar V-cb vertical bar of the Cabibbo-Kobayashi-Maskawa matrix is measured using semileptonic B-s(0) decays produced in proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb(-1). Rates of B-s0 -> D-s(-) mu(+)nu(mu) and B-s0 -> D-s*(-) mu(+)nu(mu) decays are analyzed using hadronic form-factor parametrizations derived either by Caprini, Lellouch and Neubert (CLN) or by Boyd, Grinstein and Lebed (BGL). The measured values of vertical bar V-cb vertical bar are (41.4 +/- 0.6 +/- 0.9 +/- 1.2) x 10(-3) and (42.3 +/- 0.8 +/- 0.9 +/- 1.2) x 10(-3) in the CLN and BGL parametrization, respectively. The first uncertainty is statistical, the second systematic, and the third is due to the external inputs used in the measurement. These results are in agreement with those obtained from decays of B+ and B-0 mesons. They are the first determinations of vertical bar V-cb vertical bar at a hadron-collider experiment and the first using B-s(0) meson decays.
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T2K Collaboration(Abe, K. et al), Antonova, M., Cervera-Villanueva, A., Fernandez, P., Izmaylov, A., & Novella, P. (2020). Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam. Phys. Rev. Lett., 124(16), 161802–8pp.
Abstract: Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40s and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.
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King, S. F., Molina Sedgwick, S., Parke, S. J., & Prouse, N. W. (2020). Effects of matter density profiles on neutrino oscillations for T2HK and T2HKK. Phys. Rev. D, 101(7), 076019–16pp.
Abstract: This paper explores the effects of changes in matter density profiles on neutrino oscillation probabilities, and whether these could potentially be seen by the future Hyper-Kamiokande long-baseline oscillation experiment (T2HK). The analysis is extended to include the possibility of having an additional detector in Korea (T2HKK). In both cases, we find that these effects will be immeasurable, as the magnitudes of the changes in the oscillation probabilities induced in all density profile scenarios considered here remain smaller than the estimated experimental sensitivity to the oscillation probabilities of each experiment, for both appearance and disappearance channels. Therefore, we conclude that using a constant density profile is sufficient for both the T2HK and T2HKK experiments.
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Kpatcha, E., Lopez-Fogliani, D. E., Munoz, C., & Ruiz de Austri, R. (2020). Impact of Higgs physics on the parameter space of the μnu SSM. Eur. Phys. J. C, 80(4), 336–43pp.
Abstract: Given the increasing number of experimental data, together with the precise measurement of the properties of the Higgs boson at the LHC, the parameter space of supersymmetric models starts to be constrained. We carry out a detailed analysis of this issue in the framework of the μnu SSM. In this model, three families of right-handed neutrino superfields are present in order to solve the μproblem and simultaneously reproduce neutrino physics. The new couplings and sneutrino vacuum expectation values in the μnu SSM induce new mixing of states, and, in particular, the three right sneutrinos can be substantially mixed with the neutral Higgses. After diagonalization, the masses of the corresponding three singlet-like eigenstates can be smaller or larger than the mass of the Higgs, or even degenerated with it. We analyze whether these situations are still compatible with the experimental results. To address it we scan the parameter space of the Higgs sector of the model. In particular, we sample the μnu SSM using a powerful likelihood data-driven method, paying special attention to satisfy the constraints coming from Higgs sector measurements/limits (using HiggsBounds and HiggsSignals), as well as a class of flavor observables such as B and μdecays, while muon g-2 is briefly discussed. We find that large regions of the parameter space of the μnu SSM are viable, containing an interesting phenomenology that could be probed at the LHC.
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