Yao, D. L., Fernandez-Soler, P., Guo, F. K., & Nieves, J. (2020). New parametrization of the form factors in (B)over-bar -> Dl(nu)over-bar(l) decays. Phys. Rev. D, 101(3), 034014–7pp.
Abstract: A new model-independent parametrization is proposed for the hadronic form factors in the semileptonic (B) over bar -> Dl (nu) over bar (l) decay. By a combined consideration of the recent experimental and lattice QCD data, we determine precisely the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cb vertical bar = 41.01(75) x 10(-3) and the ratio R-D = BR((B) over bar -> D tau(nu) over bar (tau))/BR((B) over bar -> Dl (nu) over bar (l)) = 0.301(5). The coefficients in this parametrization, related to phase shifts by sumrulelike dispersion relations and hence called phase moments, encode important scattering information of the (B) over bar (D) over bar interactions which are poorly known so far. Thus, we give strong hints about the existence of at least one bound and one virtual (B) over bar (D) over bar S-wave 0(+) states, subject to uncertainties produced by potentially sizable inelastic effects. This formalism is also applicable for any other semileptonic processes induced by the weak b -> c transition.
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Bruschini, R., & Gonzalez, P. (2020). Radiative decays in charmonium beyond the p/m approximation. Phys. Rev. D, 101(1), 014027–16pp.
Abstract: We analyze the theoretical description of radiative decays in charmonium. We use an elementary emission decay model to build the most general electromagnetic transition operator. We show that accurate results for the widths can be obtained from a simple quark potential model reasonably fitting the spectroscopy if the complete form of the operator is used instead of its standard p/m approximation and the experimental masses are properly implemented in the calculation.
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Raj, N., Takhistov, V., & Witte, S. J. (2020). Presupernova neutrinos in large dark matter direct detection experiments. Phys. Rev. D, 101(4), 043008–10pp.
Abstract: The next Galactic core-collapse supernova (SN) is a highly anticipated observational target for neutrino telescopes. However, even prior to collapse, massive dying stars shine copiously in “pre-supernova” (pre-SN) neutrinos, which can potentially act as efficient SN warning alarms and provide novel information about the very last stages of stellar evolution. We explore the sensitivity to pre-SN neutrinos of large-scale direct dark matter detection experiments, which, unlike dedicated neutrino telescopes, take full advantage of coherent neutrino-nucleus scattering. We find that argon-based detectors with target masses of O(100)tons (i.e., comparable in size to the proposed ARGO experiment) operating at sub-keV thresholds can detect O(10-100) pre-SN neutrinos coming from a source at a characteristic distance of similar to 200 pc, such as Betelgeuse (alpha Orionis). Large-scale xenon-based experiments with similarly low thresholds could also be sensitive to pre-SN neutrinos. For a Betelgeuse-type source, large-scale dark matter experiments could provide a SN warning siren similar to 10 hours prior to the explosion. We also comment on the complementarity of large-scale direct dark matter detection experiments and neutrino telescopes in the understanding of core-collapse SN.
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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). Determination of quantum numbers for several excited charmed mesons observed in B- -> D*(+)pi(-) pi(-) decays. Phys. Rev. D, 101(3), 032005–24pp.
Abstract: A four-body amplitude analysis of the B- -> D*(+)pi(-) pi(-) decay is performed, where fractions and relative phases of the various resonances contributing to the decay are measured. Several quasi-model-independent analyses are performed aimed at searching for the presence of new states and establishing the quantum numbers of previously observed charmed meson resonances. In particular the resonance parameters and quantum numbers are determined for the D-1 (2420), D-1 (2430), D-0 (2550), D-1* (2600), D-2 (2740) and D-3*(2750) states. The mixing between the D-1 (2420) and D-1 (2430) resonances is studied and the mixing parameters are measured. The dataset corresponds to an integrated luminosity of 4.7 fb(-1), collected in proton-proton collisions at center-of-mass energies of 7, 8 and 13 TeV with the LHCb detector.
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Centelles Chulia, S., Rodejohann, W., & Saldana-Salazar, U. J. (2020). Two-Higgs-doublet models with a flavored Z(2) symmetry. Phys. Rev. D, 101(3), 035013–12pp.
Abstract: Two-Higgs-doublet models usually consider an ad-hoc Z(2) discrete symmetry to avoid flavor changing neutral currents. We consider a new class of two-Higgs-doublet models where Z(2) is enlarged to the symmetry group F(sic)Z(2), i.e., an inner semidirect product of a discrete symmetry group F and Z(2). In such a scenario, the symmetry constrains the Yukawa interactions but goes unnoticed by the scalar sector. In the most minimal scenario, Z(3)(sic)Z(2) = D-3, flavor changing neutral currents mediated by scalars are absent at tree and one-loop level, while at the same time predictions to quark and lepton mixing are obtained, namely a trivial Cabibbo-Kobayashi-Maskawa matrix and a Pontecorvo-Maki-Nakagawa-Sakata matrix (upon introduction of three heavy right-handed neutrinos) containing maximal atmospheric mixing. Small extensions allow to fully reproduce mixing parameters, including cobimaximal mixing in the lepton sector (maximal atmospheric mixing and a maximal charge-parity violating phase).
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