C. A. de S. Pires

On the Connection of Gamma-Rays, Dark Matter and Higgs Searches at LHC

Motivated by the upcoming Higgs analyzes we investigate the importance of the complementarity of the Higgs boson chase on the low mass WIMP search in direct detection experiments and the gamma-ray emission from the Galactic Center measured by the Fermi-LAT telescope in the context of the

Naturally light right-handed neutrinos in a 3-3-1 Model

SU(3)_cotimes SU(3)_Lotimes U(1)_N

Explaining the Higgs decays at the LHC with an extended electroweak model

. We obtain the relic abundance, thermal cross section, the WIMP-nucleon cross section in the low mass regime and network them with the branching ratios of the Higgs boson in the model. We conclude that the Higgs boson search has a profound connection to the dark matter problem in our model, in particular for the case that (

Discrete symmetries, invisible axion, and lepton number symmetry in an economic 3-3-1 model

M_{WIMP} 60

A 331 WIMPy Dark Radiation Model

GeV, consequently ruling out any attempt to explain the Fermi-LAT observations.

Left-right SU ( 3 ) L × SU ( 3 ) R × U ( 1 ) X model with light, keV, and heavy neutrinos

Abstract In this work we show that light right-handed neutrinos, with mass in the sub-eV scale, is a natural outcome in a 3–3–1 model. By considering effective dimension five operators, the model predicts three light right-handed neutrinos, weakly mixed with the left-handed ones. We show also that the model is able to explain the LSND experiment and still be in agreement with solar and atmospheric data for neutrino oscillation.

Neutrino decay and neutrinoless double beta decay in a 3-3-1 model

We show that the observed enhancement in the diphoton decays of the recently discovered new boson at the LHC, which we assume to be a Higgs boson, can be naturally explained by a new doublet of charged vector bosons from extended electroweak models with SU(3)C⊗SU(3)L⊗U(1)X symmetry. These models are also rather economical in explaining the measured signal strengths, within the current experimental errors, demanding fewer assumptions and less parameters tuning. Our results show a good agreement between the theoretical expected sensitivity to a 126–125xa0GeV Higgs boson, and the experimental significance observed in the diphoton channel at the 8xa0TeV LHC. Effects of an invisible decay channel for the Higgs boson are also taken into account, in order to anticipate a possible confirmation of deficits in the branching ratios into ZZ∗, WW∗, bottom quarks, and tau leptons.

keV right-handed neutrinos from type II seesaw mechanism in a 3-3-1 model

We show that Peccei-Quinn and lepton number symmetries can be a natural outcome in a 3-3-1 model with right-handed neutrinos after imposing a Z11^ Z2 symmetry. This symmetry is suitably accommodated in this model when we augment its spectrum by including merely one singlet scalar field. We work out the breaking of the Peccei-Quinn symmetry, yielding the axion, and study the phenomenological consequences. The main result of this work is that the solution to the strong CP problem can be implemented in a natural way, implying an invisible axion phenomenologically unconstrained, free of domain wall formation, and constituting a good candidate for the cold dark matter. DOI: 10.1103/PhysRevD.68.115009

Scalar Bilepton Dark Matter

Recent observations suggest that the number of relativistic degrees of freedom in the early universe might exceed what is predicted in the standard cosmological model. If even a small, percent-level fraction of dark matter particles are produced relativistically, they could mimic the effect of an extra realistic species at matter–radiation equality while obeying BBN, CMB and Structure Formation bounds. We show that this scenario is quite naturally realized with a weak-scale dark matter particle and a high-scale “mother” particle within a well-motivated 3-3-1 gauge model, which is particularly interesting for being consistent with electroweak precision measurements, with recent LHC results, and for offering a convincing explanation for the number of generations in the Standard Model.

Explaining ATLAS and CMS Results Within the Reduced Minimal 3-3-1 model

We construct a full left-right model for the electroweak interactions based on the SU(3){sub L} x SU(3){sub R} x U(1){sub X} gauge symmetry. The fermion content of the model is such that anomaly cancellation restricts the number of families to be a multiple of three. One of the most important features of the model is the joint presence of three light active neutrinos, three additional neutrinos at keV mass scale, and six heavy ones with masses around 10{sup 11} GeV. They form a well-motivated part of the spectrum in the sense that they address challenging problems related to neutrino oscillation, warm dark matter, and baryogenesis through leptogenesis.