Related papers: Supersymmetric QCD corrections to the W-boson widt…
We calculate the supersymmetric ${\cal O}(\alpha_s)$ QCD corrections to the width of the decay $H^+ \rightarrow \st\bar{\sb}$ within the Minimal Supersymmetric Standard Model. We find that the QCD corrections are significant, but that they…
We compute supersymmetric QCD and supersymmetric electroweak corrections to the b and t quark masses and to the $\tau$ lepton mass in the presence of CP phases valid for all $\tan\beta$. The analysis includes one loop diagrams arising from…
The four-loop QCD corrections to the electroweak $\rho$-parameter arising from top and bottom quark loops are computed. Specifically we evaluate the missing ``non-singlet'' piece. Using algebraic methods the amplitude is reduced to a set of…
In this paper we compute one-loop corrections to masses and couplings in the minimal supersymmetric standard model. We present explicit formulae for the complete corrections and a set of compact approximations which hold over the unified…
Measurements of electroweak precision observables at future electron-positron colliders, such as the CEPC, FCC-ee, and ILC, will be sensitive to physics at multi-TeV scales. To achieve this sensitivity, precise predictions for the Standard…
We present the analytic calculation of the two-loop QCD corrections to the decay width of a Higgs boson into a photon and a $Z$ boson. The calculation is carried out using integration-by-parts identities for the reduction to master…
We calculate the one-loop QCD corrections for the decay of an off-shell vector boson with vector couplings into two pairs of quarks of equal or unequal flavours keeping all orders in the number of colours. These matrix elements are relevant…
We present an analysis of two-loop mixed QCD and electroweak corrections to the decay of the Z boson into light quarks. We find that the naive factorization of QCD and electroweak corrections does not describe correctly the two-loop…
In the minimal supersymmetric model (MSSM), the upper limit of the lightest Higgs boson mass, $\mhl$, depends strongly on the top quark mass, $m_t$. We have computed the dominant two-loop radiative corrections to this upper limit of $\mhl$…
The electroweak corrections at the order of $O(\alpha_{ew}m_{t(b)}^2/m_W^2)$ to the partial widths of the $\tilde{t}_2 \to \tilde{g} + t$ and $\tilde{g} \to \tilde{t}_1 + \bar{t} $ decays (depending on the masses of the particles involved)…
We study the impact of the full ${\cal O}(\alpha_{s})$ QCD and ${\cal O}(\alpha_{ew})$ electroweak (EW) radiative corrections to the $e^+e^- \to t \bar t Z^0$ process in the standard model (SM), and investigate the dependence of the…
We calculate the one-loop QCD corrections to $t\rightarrow \tilde t_1 \tilde \chi^0_j$ using dimensional reduction scheme, including QCD and supersymmetric QCD corrections. The analytic expressions for the corrections to the decay width are…
We present in analytic form the three-loop O(\alpha_s^2) correction to the H -> gg partial width of the standard-model Higgs boson with intermediate mass M_H << 2 M_t. Its knowledge is required because the O(\alpha_s) correction is so…
The three-loop QCD contributions to the vacuum polarization functions of the $Z$ and $W$ bosons at zero momentum are calculated. The top quark is considered to be massive and the other quarks massless. Using these results, we calculate the…
We calculate one-loop R-parity violating corrections to the top quark decay into a bottom quark and a polarized W-gauge boson. The corrections are presented according to the total corrections, the longitudinal corrections and the transverse…
We reevaluate the vacuum polarization functions for electroweak gauge bosons at three loops in QCD, employing state-of-the-art perturbative techniques. We apply these results to determine the ${\mathcal{O}}(\alpha \alpha_s^2)$ corrections…
We compute the one-loop QCD amplitudes for the decay of an off-shell vector boson with vector couplings into a quark-antiquark pair accompanied by two gluons keeping, for the first time, all orders in the number of colours. Together with…
QCD corrections to the electroweak one-loop result for the partial width $\Gamma(H\rightarrow b\bar{b})$ are studied. For the decay channel into bottom quarks the rate is affected by a virtual top quark through electroweak interactions. The…
We present the first full analytic results of next-to-next-to-leading order (NNLO) QCD corrections to the top-quark decay width $\Gamma(t\to Wb)$ by calculating the imaginary part of three-loop top-quark self-energy diagrams. The results…
The electroweak corrections at one-loop level to the process $H\rightarrow t{\bar t}$ are calculated, especially the fresh top mass value announced recently by CDF is concerned. For $M_H < 1. TeV$ where a perturbative calculation is valid,…