The low energy effective theory ($\sim$ TeV) of the little-Higgs model with $SU(6)/Sp(6)$, as proposed by Low, Skiba and Smith (LSS), exhibits a two-Higgs doublet (2HDM) structure. symmetry dictates interesting Yukawa patterns, translating to non-trivial fermion couplings both Higgs doublets. scalars fermions can induce flavor changing neutral currents (FCNC), which get constraints from physics...

The Muon g-2 experiment at FERMILAB has confirmed the muon anomalous magnetic moment anomaly with an error bar 15% smaller and a different central value compared previous Brookhaven result. combined results from show difference theory significance of $4.2\sigma$, strongly indicating presence new physics. In light this result, we discuss Two Higgs Doublet model augmented by Abelian gauge symmetr...

A bstract Symmetries of the Two-Higgs-Doublet Model (2HDM) potential that can be extended to whole Lagrangian, i.e. CP-symmetries CP1, CP2, CP3 and Higgs-family symmetries Z 2 , U(1) SO(3) are discussed. Sufficient necessary conditions in terms constraints on masses physical couplings for respect each these found. Each symmetry realized through several alternative cases, case being a set relati...

Present data do not rule out the light neutral Higgs particle h or A in the framework of the general 2HDM. The discovery reach/exclusion limits of the Yukawa process Z → f f̄h/A, (f = b quark or τ lepton) at LEP I and of the gluon-gluon fusion at HERA is discussed. In addition the possible search for very light Higgs particle in γγ fusion at low energy NLC is described. Invited talk at the XXXIs...

Flavor Changing Neutral Current decays of the top quark within the strict context of the Standard Model are known to be extremely rare. In fact, they are hopelessly undetectable at the Tevatron, LHC and LC in any of their scheduled upgradings. Therefore, if a few of these events eventually show up in the future we will have certainly discovered new physics. We argue that this could well be the ...

In a recent re-analysis of the Standard Model (SM) β-function for the effective neutrino mass operator, we found that the previous results were not entirely correct. Therefore, we consider the analogous dimension five operators in a class of Two Higgs Doublet Models (2HDM’s) and the Minimal Supersymmetric Standard Model (MSSM). Deriving the renormalization group equations for these effective op...

We study the phenomenology of the µ − τ and e − τ lepton flavour violation (LFV) in a general two Higgs Doublet Model (2HDM) including the supersymmetric case. We consider several LFV decay modes of the charged fermion τ , namely τ → l j γ, τ → l j l k l k and τ → l j η. The predictions and the correlations among the rates of the above processes are computed. In particular, it is shown that τ →...