Related papers: Vector Higgs bosons and possible suppression of fl…
We discuss a minimal extension to the standard model in which there are two Higgs bosons and, in addition to the usual fermion content, two fermion doublets and one fermion singlet. The little hierachy problem is solved by the vanishing of…
CP4 3HDM is a peculiar three-Higgs-doublet model in which a single symmetry leads to tight constraints on the scalar and Yukawa sectors. In this models, tree-level flavor-changing neutral couplings are unavoidable; however, as previously…
We study the phenomenological consequences of a four site Higgsless model based on the SU(2)_L x SU(2)_1 x SU(2)_2 x U(1)_Y gauge symmetry, which predicts two neutral and four charged extra gauge bosons, Z_{1,2} and W_{1,2}. The model…
A vector-like extension of the standard model for heavier quarks and leptons with $SU(2)\times U(1)$ gauge symmetry and only one Higgs doublet is examined. This scheme incorporates infinitely many fermions and avoids the appearance of a…
On the verge of conclusive checks on the Standard Model by the LHC, we discuss some of the basic assumptions. The reason for this analysis stems from a recent proposal of an Electroweak Model based on a nonlinearly realized gauge group…
Classical scale invariance (CSI) may be one of the solutions for the hierarchy problem. Realistic models for electroweak symmetry breaking based on CSI require extended scalar sectors without mass terms, and the electroweak symmetry is…
We study a three Higgs doublet model where one doublet is inert and the other two doublets are active. Flavor changing neutral currents are avoided at tree-level by imposing a softly broken $Z'_2$ symmetry and we consider type I and type II…
We discuss two Higgs doublet models with a softly-broken discrete $\mathbb{S}_3$ symmery, where the mass matrix for charged-leptons is predicted as the diagonal form in the weak eigenbasis of lepton fields. Similar to an introduction of…
We study a simplified model of two colourless heavy vector resonances in the singlet representation of $SU(2)_{L}$, with zero and unit hypercharge. We discuss mixing with the Standard Model gauge bosons due to electroweak symmetry breaking,…
We study Little Higgs models based on a SU(3)_1 x SU(3)_2 global symmetry and with two scales (the two vacuum expectation values f_{1,2}) substantially different. We show that all the extra vector boson fields present in these models may be…
We examine the simplest realization of the linear seesaw mechanism within the Standard Model gauge structure. Besides the standard scalar doublet, there are two lepton-number-carrying scalars, a nearly inert SU2 doublet and a singlet.…
The tree-level flavour-changing neutral currents in the two-Higgs-doublet models can be suppressed by protecting the breaking of either flavour or flavour-blind symmetries, but only the first choice, implemented by the application of the…
In this Thesis we have investigated some effects appearing in top quark and Higgs boson decays with flavor changing neutral currents (FCNC) in the framework of generic Two Higgs Doblet Models (2HDM) and the Minimal Supersymmetric Standard…
We present a comprehensive analysis of the Higgs boson spectra in several versions of the supersymmetric left--right model based on the gauge symmetry $SU(3)_c \times SU(2)_L \times SU(2)_R \times U(1)_{B-L}$. A variety of symmetry breaking…
We propose a minimal modification of the standard model, remarkable in its simplicity, which may solve the strong CP problem. It employs three Higgs doublets with interactions taken to be invariant under a flavor symmetry. Both CP and the…
The unified compositeness of leptons, quarks and Higgs bosons is proposed as a possible scenario for New Physics beyond the Standard Model. The following topics of the scenario are briefly discussed: - Chiral gauge exceptional symmetry E_6…
The fundamental constraint on two Higgs doublet models comes from the requirement of sufficiently suppressing flavor-changing neutral currents. There are various standard approaches for dealing with this problem, but they all tend to share…
The rather precise knowledge of the mass of the Higgs boson and of its couplings has important consequences for the physical phenomena taking place at the Fermi scale. We analyze some of these implications in the most motivated frameworks…
We consider the scenario where the composite Higgs arising as a pNGB in a two-site model with a non-local term included. Constraints from pion scattering and electroweak precision test are considered. We discuss the effects of composite…
The vertex H^+_\alpha W^-h^0_\beta, involving the gauge boson W^+- and the charged (H^+-_\alpha) and neutral Higgs bosons (h^0_\beta), arises within the context of many extensions of the SM, and it can be used to probe the quantum numbers…