相关论文: Upper Bound on R_b in Two Higgs Doublet Model from…
We study the effect of one universal extra dimension on the branching ratios of the lepton flavor violating processes \mu\to e\gamma and \tau\to \mu\gamma in the general two Higgs doublet model. We observe that these new effects are tiny…
We show that Yukawa couplings of bottom quarks and tau leptons can be unified in a non-supersymmetric SU(5) model. We introduce an arbitrary number of right-handed neutrinos. Their masses and Yukawa couplings that satisfy the unification…
We analyze the one loop corrections to leptonic W and Z decays in an R-parity violating extension to the Minimal Supersymmetric Standard Model (MSSM). We find that lepton universality violation in the Z line-shape variables alone would…
The recent measurement on the muon anomalous magnetic moment $a_\mu$ shows a $2.6\sigma$ deviation from the standard model value. We show that it puts strong constraints on the parameter space of the two-higgs doublet model (2HDM) II. The…
Within a Two-Higgs-Doublet Model (2HDM) a search for a light Higgs boson in the mass range of 4-12 GeV has been performed in the Yukawa process e+e- -> b bbar A/h -> b bbar tau+tau-, using the data collected by the OPAL detector at LEP…
In this paper, we study an extension of the standard model with a vector-like generation of leptons. This model provides a viable dark matter candidate and a possibility to enhance the Higgs decay rate into a pair of photons. We evaluate…
We consider a Z_2-symmetric Two Higgs Doublet Model (2HDM), where the vacuum expectation values of both doublets are non-vanishing. Unitarity constraints for the SM-like 2HDM are analyzed for the mass of the lightest Higgs boson in the…
The Yukawa corrections of order ${\cal O}(\alpha_{ew}m_{t(b)}^2/m_W^2)$, ${\cal O}(\alpha_{ew}m_{t(b)}^3/m_W^3)$ and ${\cal O}(\alpha_{ew}m_{t(b)}^4/m_W^4)$ to the width of sbottom decay into lighter stop plus charged Higgs boson are…
This paper is divided into two parts. In the first part we analyze the consequences, for the LHC, of gauge and third family Yukawa coupling unification with a particular set of boundary conditions defined at the GUT scale. We perform a…
We write down the renormalization-group equations for the Yukawa-coupling matrices in a general multi-Higgs-doublet model. We then assume that the matrices of the Yukawa couplings of the various Higgs doublets to right-handed fermions of…
We present a comprehensive analysis of the Non-Minimal Supersymmetric Standard Model (NMSSM) for large values of $\tan\beta$, the ratio of the vacuum expectation values of the two Higgs doublets, which arise when we impose the constraint of…
We consider two Higgs doublet models with a softly broken U(1) symmetry, for various limiting values of the scalar mixing angles $\alpha$ and $\beta$. These correspond to the Standard Model Higgs particle being the lighter CP-even scalar…
A remarkable achievement of the realistic superstring standard--like models is the successful prediction of the top quark mass, assuming the Minimal Supersymmetric Standard Model spectrum below the string scale. Recently it was shown that…
We consider the Two Higgs Doublet Model (2HDM) of type III which leads to Flavour Changing Neutral Currents (FCNC) at tree level. In the framework of this model we can use an appropriate form of the Yukawa Lagrangian that makes the type II…
Current muon anomalous magnetic moment data have challenged the SM, and seems to open a window to new Physics. Since the difference between SM and experimental predictions is approximately $2.6\sigma$. In the framework of the General Two…
A global analysis is performed using the latest data from LEP and SLC. Constraints on the electroweak universal parameters ($S,T,U$) and on the masses of the top quark and Higgs boson within the Standard Model (SM) are investigated. The…
We discuss lepton flavor violation (LFV) associated with tau leptons in the general framework of the two Higgs doublet model, in which LFV couplings are introduced as a deviation from Model II Yukawa interaction. Parameters of the model are…
In several extensions of the Standard Model, the top quark can decay into a bottom quark and a light charged Higgs boson H+, t to bH+, in addition to the Standard Model decay t to bW. Since W bosons decay to the three lepton generations…
We examine various direct and indirect constraints on the lepton-specific two-Higgs doublet model and scrutinize the property of the Higgs bosons in the allowed parameter space. These constraints come from the precision electroweak data,…
We analyze the unconventional top quark decay mode t -> H^+ b at the quantum level within the context of general Two-Higgs-Doublet models by including the full electroweak effects from the Yukawa couplings. The results are presented in the…