Related papers: Dominant Two-Loop Electroweak Correction to H -> g…
The two-loop electroweak bosonic correction to the muon lifetime is computed using methods of asymptotic expansion. Combined with previous calculations this completes the full two-loop correction to $\Delta r$ in the Standard Model.
The electroweak $\mc O(\alpha)$ radiative corrections to the decay of the lightest MSSM Higgs boson to four leptons are presented, improved by the two-loop corrections provided by the program package FeynHiggs. We also analyze the results…
We analyze the loop induced decays of the Higgs boson into pairs of gluons and photons in the Littlest Higgs model. We find that the deviation of the partial widths for these decays relative to their Standard Model values scales with 1/f^2,…
Higher-order contributions to the precision observables \Delta r, \sin^2\theta_eff and \Gamma_l are discussed. The Higgs-mass dependence of the observables is investigated at the two-loop level, and exact results are derived for the…
We evaluate the next-to-leading-order QCD corrections of O(alpha_s^2 G_F M_t^2) to the Standard-Model l^+l^-H, ZZH, and W^+W^-H couplings in the heavy-top- quark limit. Exploiting these results together with knowledge of Delta rho to the…
Results are presented for the leading two-loop contributions of O(alpha_t alpha_s) to the masses and mixing effects in the Higgs sector of the MSSM with complex parameters. They are obtained in the Feynman-diagrammatic approach using…
We present our calculation of the two-loop corrections of ${\cal O}(\alpha_t^2)$ to the neutral Higgs boson masses of the CP-violating Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM). The calculation is performed in…
The non-decoupling effects of heavy Higgs bosons on the process $e^+e^- \to W^+_LW^-_L$ are discussed in the two Higgs-doublet model. The one-loop corrections to the cross section are calculated by using the equivalence theorem and the…
Higher-order corrections to the MSSM Higgs-boson masses are desirable for accurate predictions currently testable at the LHC. By comparing the prediction with the measured value of the discovered Higgs signal, viable parameter regions can…
We calculate the ${\cal O}(\alpha_{s})$ QCD and ${\cal O}(\alpha_{{\rm ew}})$ electroweak one-loop corrections in the Standard Model framework, to the production of an intermediate Higgs boson associated with $t\bar{t}$ pair via $\gamma…
In this article, we study the rare decay process in which a Higgs boson decays into a $Z$ boson and a photon. In the first part of the paper, we analyze the Standard Model (SM) contributions to the corresponding decay width, including the…
The Higgs boson decay to a massive bottom quark pair provides the dominant contribution to the Higgs boson width. We present an exact result for such a decay induced by the bottom quark Yukawa coupling with next-to-next-to-leading order…
We study one loop electroweak corrections to the production of a pair of charged Higgs bosons through an intermediate $Z$-boson or photon. In particular, we consider the effects of graphs with top and bottom quarks and squarks in the loop…
We calculate the full ${\cal O}(\alpha_{ew})$ electroweak corrections to the Higgs pair production process $e^+ e^- \to H H Z$ at an electron-positron linear collider in the standard model, and analyze the dependence of the Born cross…
We revisit the radiative decays of the Higgs boson to a fermion pair $h\rightarrow f\bar{f}\gamma$ where $f$ denotes a fermion in the Standard Model (SM). We include the chirality-flipping diagrams via the Yukawa couplings at the order…
We calculate the b-dependent self-energy of the top quark at O(g^2 \alpha_s) by using a general massive two-loop algorithm proposed in a previous article. From this we derive by unitarity the O(\alpha_s) radiative corrections to the decay…
Among the O(alpha_s tan beta) contributions to the Wilson coefficients C_7 and C_8, relevant for the decay bar{B} -> X_s gamma, those induced by two-loop diagrams with charged-Higgs-boson exchange and squark-gluino corrections are…
We present a computation of the O(at*as + at^2) two--loop corrections to the MSSM Higgs masses. An appropriate use of the effective potential approach allows us to obtain simple analytical formulae, valid for arbitrary values of mA and of…
An updated global analysis within the Standard Model (SM) of all relevant electroweak precision and Higgs boson search data is presented with special emphasis on the implications for the Higgs boson mass, M_H. Included are, in particular,…
We study the scheme dependence of the two-loop expression for the $\rho$-parameter of the Standard Model in the heavy $t$-quark mass limit $m_{t} \gg m_{w}$. In the $\ms$-scheme the two-loop electroweak correction to the ${\cal…