|
|
Centelles Chulia, S., Srivastava, R., & Valle, J. W. F. (2018). Seesaw roadmap to neutrino mass and dark matter. Phys. Lett. B, 781, 122–128.
Abstract: We describe the many pathways to generate Majorana and Dirac neutrino mass through generalized dimension-5 operators a la Weinberg. The presence of new scalars beyond the Standard Model Higgs doublet implies new possible field contractions, which are required in the case of Dirac neutrinos. We also notice that, in the Dirac neutrino case, the extra symmetries needed to ensure the Dirac nature of neutrinos can also be made responsible for stability of dark matter.
|
|
|
|
Centelles Chulia, S., Srivastava, R., & Valle, J. W. F. (2017). Generalized bottom-tau unification, neutrino oscillations and dark matter: Predictions from a lepton quarticity flavor approach. Phys. Lett. B, 773, 26–33.
Abstract: We propose an A(4) extension of the Standard Model with a Lepton Quarticity symmetry correlating dark matter stability with the Dirac nature of neutrinos. The flavor symmetry predicts (i) a generalized bottom-tau mass relation involving all families, (ii) small neutrino masses are induced a la seesaw, (iii) CP must be significantly violated in neutrino oscillations, (iv) the atmospheric angle theta(23) lies in the second octant, and (v) only the normal neutrino mass ordering is realized.
|
|
|
|
Centelles Chulia, S., Ma, E., Srivastava, R., & Valle, J. W. F. (2017). Dirac neutrinos and dark matter stability from lepton quarticity. Phys. Lett. B, 767, 209–213.
Abstract: We propose to relate dark matter stability to the possible Dirac nature of neutrinos. The idea is illustrated in a simple scheme where small Dirac neutrino masses arise from a type-I seesaw mechanism as a result of a Z(4) discrete lepton number symmetry. The latter implies the existence of a viable WIMP dark matter candidate, whose stability arises from the same symmetry which ensures the Diracness of neutrinos.
|
|
|
|
Centelles Chulia, S., Srivastava, R., & Valle, J. W. F. (2016). CP violation from flavor symmetry in a lepton quarticity dark matter model. Phys. Lett. B, 761, 431–436.
Abstract: We propose a simple Delta (27) circle times Z(4) model where neutrinos are predicted to be Dirac fermions. The smallness of their masses follows from a type-I seesaw mechanism and the leptonic CP violating phase correlates with the pattern of Delta(27) flavor symmetry breaking. The scheme naturally harbors a WIMP dark matter candidate associated to the Dirac nature of neutrinos, in that the same Z(4) lepton number symmetry also ensures dark matter stability.
|
|
|
|
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).
|
|
