Related papers: A two-Higgs-doublet model without flavor-changing …
A study of $R_b$ and $R_c$ is presented in the context of a Two Higgs Doublet Model (2HDM) with flavor changing scalar currents (FCSC). Implications of the model for the $\rho$-parameter and for $b\to s\gamma$ are also considered. The…
We propose an alternative method of constructing two Higgs-doublet models free from scalar mediated FCNC couplings at the tree-level. In a toy scenario, we have presented semi realistic textures for the Yukawa matrices, which can reproduce…
We construct extensions of the Standard Model with two Higgs doublets, where there are flavour changing neutral currents both in the quark and leptonic sectors, with their strength fixed by the fermion mixing matrices $V_{CKM}$ and…
We discuss the Flavor-Changing Neutral Current (FCNC) decays of the top quark t -> c Vi Vj (Vi=gamma, Z, g) in the framework of the Standard Model (SM) and in a two-higgs doublet model (2HDM) with tree-level FCNC couplings. While in the SM…
It is well known that generic two-Higgs-doublet models (2HDMs) suffer from potentially large Higgs-mediated flavor-changing neutral current (FCNC) problem, unless additional symmetries are imposed on the Higgs fields thereby respecting the…
Two Higgs-doublet models usually consider an ad-hoc $\mathbb{Z}_2$ discrete symmetry to avoid flavor changing neutral currents. We consider a new class of two Higgs-doublet models where $\mathbb{Z}_2$ is enlarged to the symmetry group…
In the two-Higgs-Doublet model the alignment of the Yukawa flavour matrices of the two scalar doublets guarantees the absence of tree-level flavour-changing neutral couplings. The resulting fermion-scalar interactions are parameterized in…
In the left-right symmetric model based on $SU(2)_L\times SU(2)_R\times U(1)_{B-L}$ gauge symmetry, there appear heavy neutral scalar particles mediating quark flavor changing neutral currents (FCNCs) at tree level. We consider a situation…
A comprehensive phenomenological analysis of a two Higgs doublet model, with flavor changing scalar currents at the tree level, called model III, is presented. Constraints from existing experimental information especially on (Delta F)=2…
In this paper, we study the extended Standard Model (SM) with an extra Higgs doublet and right-handed neutrinos. If the symmetry to distinguish the two Higgs doublets is not assigned, flavor changing neutral currents (FCNCs) involving the…
Consequences of a specific class of two Higgs doublet models in which the Higgs induced tree level flavour changing neutral currents (FCNC) display minimal flavour violation (MFV) are considered. These FCNC are fixed in terms of the CKM…
We consider a 4-Higgs-doublet model in which each Higgs doublet gives mass to one of the fermion sets $\{ m_t\}$, $\{ m_b,m_\tau,m_c \}$, $\{ m_\mu,m_s \}$, and $\{ m_d,m_u,m_e \}$. The sets have the feature that within each of them the…
The charged fermion mass matrices are invariant under $U(1)^3$ symmetry linked to the fermion number transformation. Under the condition that the definition of this symmetry in arbitrary weak basis does not depend upon Higgs parameters such…
Two-Higgs-doublet models come with an augmented parameter space which allows them to possibly solve some of the shortcomings of the Standard Model, and opens the window to a plethora of new phenomena to be discovered. The introduction of…
In this letter we show a general description about flavor-changing neutral currents (FCNC) mediated by scalars. The analysis is extended at two-loop level for the Two-Higgs Doublet Model type-III because others models have strong…
We study a variant of the 3HDM, referred to as the BGL-3HDM, incorporating a $U(1)_1\times U(1)_2$ symmetry, which can distinguish the primary sources of mass for different fermion generations. In the version considered here, the Yukawa…
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…
We consider the standard model with two Higgs doublets with the most general Yukawa coupling terms (``type III''). In the model, the neutral-Higgs-mediated flavor-changing neutral currents (FCNC's) are allowed, but must be reasonably…
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…
We discuss theoretical and phenomenological aspects of two-Higgs-doublet extensions of the Standard Model. In general, these extensions have scalar mediated flavour changing neutral currents which are strongly constrained by experiment.…