F. Ochoa

Diphoton decay for a 750 GeV scalar boson in a SU(6)⊗U(1)X model

In the context of a nonuniversal and anomaly free U(1)X extension of the standard model, we examine the decay of a 750 GeV scalar singlet state, ξχ , as a possible explanation of the observed diphoton excess announced by the ATLAS and CMS collaborations at CERN-LHC collider. The one-loop decay to photons is allowed through three heavy singlet quarks and one charged Higgs boson into the loop. We obtain, for different width approximations and for masses of the exotic singlet quarks in the region [900, 3000] GeV, a production cross section σ(pp → ξχ → γ γ ) compatible with ATLAS and CMS collaborations data. We also include another scalar singlet, σ , as a dark matter candidate that may couple with the 750 GeV scalar at tree level with production cross sections in agreement with ATLAS and CMS.

SU(3)(c) x SU(3)(L) x U(1)(X) models for beta arbitrary and families with mirror fermions

A detailed and general study of the fermionic structure of the 331 models with {beta} arbitrary is carried out based on the criterion of cancellation of anomalies. We consider models with an arbitrary number of lepton and quark generations, but which require associating only one lepton and one quark SU(3){sub L} multiplet for each generation, and at most one right-handed singlet per each left-handed fermion. We see that the number of quark left-handed multiplets must be 3 times the number of leptonic left-handed multiplets. Furthermore, we consider a model with four families and {beta}=-1/{radical}(3) where the additional family corresponds to a mirror fermion of the third generation of the standard model. We also show how to generate ansatz about the mass matrices of the fermions according to the phenomenology. In particular, it is possible to get a natural fit for the neutrino hierarchical masses and mixing angles. Moreover, by means of the mixing between the third quark family and its mirror fermion, a possible solution for the A{sub FB}{sup b} discrepancy is obtained.A detailed and general study of the fermionic structure of the 331 models with \beta arbitrary is carried out based on the criterion of cancellation of anomalies. We consider models with an arbitrary number of lepton and quark generations, but requiring to associate only one lepton and one quark SU(3) _{L} multiplet for each generation, and at most one right-handed singlet per each left-handed fermion. We see that the number of quark left-handed multiplets must be three times the number of leptonic left-handed multiplets. Furthermore, we consider a model with four families and \beta =-1/\sqrt{3} where the additional family corresponds to a mirror fermion of the third generation of the Standard Model. We also show how to generate ansatzs about the mass matrices of the fermions according to the phenomenology. In particular, it is possible to get a natural fit for the neutrino hierarchical masses and mixing angles. Moreover, by means of the mixing between the third quark family and its mirror fermion, a possible solution for the A_{FB}^{b} discrepancy is obtained.

Scalar sector of the SU(3)c⊗SU(3)L⊗U(1)X model

A complete study of the Higgs sector of the

Diphoton decay for a 750 GeV scalar boson in a

SU(3)_{c}\otimes SU(3)_{L}\otimes U(1)_{X}

SU(6)\otimes U(1)_{X}

model is carried out, obtaining all possible cases of vacuum expectation values that permit the spontaneous symmetry breaking pattern

model

SU(3)_{L}\otimes U(1)_{X}\to SU(2)_{L}\otimes U(1)_{Y}\to U(1)_{Q}.

Bead, hoop and spring as a classical spontaneous symmetry breaking problem

We find the most general Higgs potentials that contain three triplets of Higgs and one sextet. A detailed study of the scalar sector for different models with three Higgs triplets is done. The models end up in an electroweak two Higgs doublet model after the first symmetry breakdown; we find that the low energy limit depends on a trilinear parameter of the Higgs potential, and that the decoupling limit from the electroweak two Higgs doublet model to the minimal standard model can be obtained quite naturally.

SU(3)_{c} X SU(3)_{L} X U(1)_{X} models for \beta arbitrary and families with mirror fermions

We propose a new

The Scalar sector of the SU(3)(c) x SU(3)(L) x U(1)(X) model

SU(6)\otimes U(1)_{X}

The scalar sector of the

GUT model free from anomalies, with a 750 GeV scalar candidate which can decay into two photons, compatible with the recent diphoton signal reported by ATLAS and CMS collaborations. This model gives masses to all fermions and may explain the 750GeV signal through one loop decays to