Related papers: Large 2HDM(II) one-loop corrections in leptonic ta…
If tan(beta) is large, down-type quark mass matrices and Yukawa couplings cannot be simultaneously diagonalized, and flavour violating couplings of the neutral Higgs bosons are induced at the 1-loop level. These couplings lead to…
The one-loop branching ratios for the process Z->h(A)+gamma are calculated in the general Two Higgs Doublet Model (Model II) taking into account existing constraints on the model parameters. For Higgs boson masses below 50 GeV and tan beta…
The top-Yukawa-coupling enhanced two-loop corrections to the charged Higgs-boson mass in the real MSSM are presented. The contributing two-loop self-energies are calculated in the Feynman- diagrammatic approach in the gaugeless limit with…
The SU(5) unification-scale relation h_b=h_tau between the b and tau Yukawa couplings severely constrains tan beta and m_t (even more so if h_t=h_b= h_tau holds) in supersymmetric models. We examine the implications of these constraints for…
We present a complete one-loop computation of the $H^\pm \rightarrow W^\pm Z$ decay in the aligned two-Higgs-doublet model. The constraints from the electroweak precision observables, perturbative unitarity, vacuum stability and flavour…
We complete the effective potential calculation of the two-loop, top/bottom Yukawa corrections to the Higgs boson masses in the Minimal Supersymmetric Standard Model, by computing the O(at^2 + at*ab + ab^2) contributions for arbitrary…
We calculate the new physics contributions to the branching ratios of the rare decays $B \to X_s l^+ l^-$ $(l=e, \mu)$ induced by neutral Higgs bosons loop diagrams in the top quark two-Higgs-doublet model (T2HDM). From the numerical…
We study the one loop electroweak radiative corrections to $h^0\to b\bar{b}$ and $h^0\to \tau^+\tau^-$ in the framework of two Higgs doublet Model (2HDM). We evaluate the deviation of these couplings from their Standard Model (SM) values.…
The Standard-Model Higgs boson with mass $ M_H >> 2M_Z $ decays almost exclusively to pairs of $W$ and $Z$ bosons. We calculate the dominant two-loop corrections of $ O( G_F^2 M_H^4 )$ to the partial widths of these decays. In the…
We study the complete one loop contribution to H^\pm\to W^\pm V, V= Z, \gamma, both in the Minimal Supersymmetric Standard Model (MSSM) and in the Two Higgs Doublet Model (2HDM). We evaluate the MSSM contributions and compare them with the…
Singlet Higgs bosons present in extensions of the MSSM can have sizable Yukawa couplings to the b quark and the tau lepton for large values of tan(beta) at the 1-loop level. We present an effective Lagrangian which incorporates these…
The one-loop contributions to the decays of the $CP$-odd and $CP$-even scalar bosons $A\to Z\gamma\gamma$ and $\phi\to Z\gamma\gamma$ ($\phi=h,H$) are calculated within the framework of $CP$-conserving THDMs, where they are induced by box…
Results for the leading two-loop corrections of $\mathcal{O}{\left(\alpha_t^2\right)}$ from the Yukawa sector to the Higgs-boson masses of the MSSM with complex parameters are presented. The corresponding self-energies and their…
We present the currently most precise predictions for the $W$-boson mass and the leptonic effective mixing angle $\sin^2\theta_{\text{eff}}$ in the aligned Two-Higgs-Doublet Model. The evaluation includes the full one-loop result, all known…
The complete set of two-loop electroweak corrections to the decay width of the Higgs boson into two photons is presented. Two-loop contributions involving weak bosons and the top quark are computed in terms of an expansion in the Higgs…
We compute the two-loop BSM contributions to the $h\longrightarrow \gamma\gamma$ decay width in the aligned THDM. We adopt the simplifying assumptions of vanishing EW gauge couplings and vanishing mass of the SM-like Higgs boson, which…
In this manuscript the B -> pi tau nu decay is investigated in the context of the 2HDM type II extension of the SM. In particular, predictions for the ratio of semileptonic branching fractions from l = tau and l = electron, muon are…
We calculate the leading electroweak (EW) corrections to the important process of Higgs production associated with two bottom quarks at the CERN Large Hadron Collider (LHC). Our study is restricted to the Standard Model (SM). At tree-level…
The leading $m_H$ radiative correction to the Higgs decay width into a pair of weak vector bosons is calculated at the two--loop level, using the equivalence theorem in Landau gauge. The result indicates the breakdown of perturbation theory…
Models with two scalar doublets are among the simplest extensions of the Standard Model which fulfill the relation $\rho = 1$ at lowest order for the $\rho$ parameter as favored by experimental data for electroweak observables allowing only…