Kosmas, T. S., Miranda, O. G., Papoulias, D. K., Tortola, M., & Valle, J. W. F. (2015). Probing neutrino magnetic moments at the Spallation Neutron Source facility. Phys. Rev. D, 92(1), 013011–12pp.
Abstract: Majorana neutrino electromagnetic properties are studied through neutral current coherent neutrinonucleus scattering. We focus on the potential of the recently planned COHERENT experiment at the Spallation Neutron Source to probe muon-neutrino magnetic moments. The resulting sensitivities are determined on the basis of chi(2) analysis employing realistic nuclear structure calculations in the context of the quasiparticle random phase approximation. We find that they can improve existing limits by half an order of magnitude. In addition, we show that these facilities allow for standard model precision tests in the low energy regime, with a competitive determination of the weak mixing angle. Finally, they also offer the capability to probe other electromagnetic neutrino properties, such as the neutrino charge radius. We illustrate our results for various choices of experimental setup and target material.
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Boucenna, S. M., Valle, J. W. F., & Vicente, A. (2015). Predicting charged lepton flavor violation from 3-3-1 gauge symmetry. Phys. Rev. D, 92(5), 053001–7pp.
Abstract: The simplest realization of the inverse seesaw mechanism in a SU(3)(C) circle times SU(3)(L) circle times U(1)(X) gauge theory offers striking flavor correlations between rare charged lepton flavor violating decays and the measured neutrino oscillations parameters. The predictions follow from the gauge structure itself without the need for any flavor symmetry. Such tight complementarity between charged lepton flavor violation and neutrino oscillations renders the scenario strictly testable.
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Escrihuela, F. J., Forero, D. V., Miranda, O. G., Tortola, M., & Valle, J. W. F. (2015). On the description of nonunitary neutrino mixing. Phys. Rev. D, 92(5), 053009–16pp.
Abstract: Neutrino oscillations are well established and the relevant parameters determined with good precision, except for the CP phase, in terms of a unitary lepton mixing matrix. Seesaw extensions of the Standard Model predict unitarity deviations due to the admixture of heavy isosinglet neutrinos. We provide a complete description of the unitarity and universality deviations in the light-neutrino sector. Neutrino oscillation experiments involving electron or muon neutrinos and antineutrinos are fully described in terms of just three new real parameters and a new CP phase, in addition to the ones describing oscillations with unitary mixing. Using this formalism we describe the implications of nonunitarity for neutrino oscillations and summarize the model-independent constraints on heavy-neutrino couplings that arise from current experiments.
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Bonilla, C., Fonseca, R. M., & Valle, J. W. F. (2015). Consistency of the triplet seesaw model revisited. Phys. Rev. D, 92(7), 075028–7pp.
Abstract: Adding a scalar triplet to the Standard Model is one of the simplest ways of giving mass to neutrinos, providing at the same time a mechanism to stabilize the theory's vacuum. In this paper, we revisit these aspects of the type-II seesaw model pointing out that the bounded-from-below conditions for the scalar potential in use in the literature are not correct. We discuss some scenarios where the correction can be significant and sketch the typical scalar boson profile expected by consistency.
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Boucenna, S. M., Valle, J. W. F., & Vicente, A. (2015). Are the B decay anomalies related to neutrino oscillations? Phys. Lett. B, 750, 367–371.
Abstract: Neutrino oscillations are solidly established, with a hint of CP violation just emerging. Similarly, there are hints of lepton universality violation in b -> s transitions at the level of 2.6 sigma. By assuming that the unitary transformation between weak and mass charged leptons equals the leptonic mixing matrix measured in neutrino oscillation experiments, we predict several lepton flavor violating (LFV) B meson decays. We are led to the tantalizing possibility that some LFV branching ratios for B decays correlate with the leptonic CP phase delta characterizing neutrino oscillations. Moreover, we also consider implications for l(i) -> l(j)l(k)l(k) decays.
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