|
|
Bonilla, C., Herms, J., Medina, O., & Peinado, E. (2023). Discrete dark matter mechanism as the source of neutrino mass scales. J. High Energy Phys., 06(6), 078–23pp.
Abstract: The hierarchy in scale between atmospheric and solar neutrino mass splittings is investigated through two distinct neutrino mass mechanisms from tree-level and one-loop-level contributions. We demonstrate that the minimal discrete dark matter mechanism contains the ingredients for explaining this hierarchy. This scenario is characterized by adding new RH neutrinos and SU(2)-doublet scalars to the Standard Model as triplet representations of an A(4) flavor symmetry. The A(4) symmetry breaking, which occurs at the electroweak scale, leads to a residual DOUBLE-STRUCK CAPITAL Z(2) symmetry responsible for the dark matter stability and dictates the neutrino phenomenology. Finally, we show that to reproduce the neutrino mixing angles correctly, it is necessary to violate CP in the scalar potential.
|
|
|
|
Alvarado, C., Bonilla, C., Leite, J., & Valle, J. W. F. (2021). Phenomenology of fermion dark matter as neutrino mass mediator with gauged B-L. Phys. Lett. B, 817, 136292–12pp.
Abstract: We analyze a model with unbroken U(1)(B-L) gauge symmetry where neutrino masses are generated at one loop, after spontaneous breaking of a global U(1)(G) symmetry. These symmetries ensure dark matter (DM) stability and the Diracness of neutrinos. Within this context, we examine fermionic dark matter. Consistency between the required neutrino mass and the observed relic abundance indicates dark matter masses and couplings within the reach of direct detection experiments.
|
|
|
|
Bonilla, C., Centelles Chulia, S., Cepedello, R., Peinado, E., & Srivastava, R. (2020). Dark matter stability and Dirac neutrinos using only standard model symmetries. Phys. Rev. D, 101(3), 033011–5pp.
Abstract: We provide a generic framework to obtain stable dark matter along with naturally small Dirac neutrino masses generated at the loop level. This is achieved through the spontaneous breaking of the global U(1)(B-L) symmetry already present in the standard model. The U(1)(B-L) symmetry is broken down to a residual even Z(n) (n >= 4) subgroup. The residual Z(n) symmetry simultaneously guarantees dark matter stability and protects the Dirac nature of neutrinos. The U(1)(B-L) symmetry in our setup is anomaly free and can also be gauged in a straightforward way. Finally, we present an explicit example using our framework to show the idea in action.
|
|
|
|
Bonilla, C., Romao, J. C., & Valle, J. W. F. (2016). Electroweak breaking and neutrino mass: `invisible' Higgs decays at the LHC (type II seesaw). New J. Phys., 18, 033033–21pp.
Abstract: Neutrino mass generation through the Higgs mechanism not only suggests the need to reconsider the physics of electroweak symmetry breaking from a new perspective, but also provides a new theoretically consistent and experimentally viable paradigm. We illustrate this by describing the main features of the electroweak symmetry breaking sector of the simplest type-II seesaw model with spontaneous breaking of lepton number. After reviewing the relevant `theoretical' and astrophysical restrictions on the Higgs sector, we perform an analysis of the sensitivities of Higgs Boson searches at the ongoing ATLAS and CMS experiments at the LHC, including not only the new contributions to the decay channels present in the standard model (SM) but also genuinely non-SM Higgs Boson decays, such as `invisible' Higgs Boson decays to majorons. We find sensitivities that are likely to be reached at the upcoming run of the experiments.
|
|
|
|
Bonilla, C., Fonseca, R. M., & Valle, J. W. F. (2016). Vacuum stability with spontaneous violation of lepton number. Phys. Lett. B, 756, 345–349.
Abstract: The vacuum of the Standard Model is known to be unstable for the measured values of the top and Higgs masses. Here we show how vacuum stability can be achieved naturally if lepton number is violated spontaneously at the TeV scale. More precise Higgs measurements in the next LHC run should provide a crucial test of our symmetry breaking scenario. In addition, these schemes typically lead to enhanced rates for processes involving lepton flavor violation.
|
|
