Related papers: Second Order QCD Corrections to $\Gamma(t \to Wb)$
In this talk we consider the O(alpha_s) radiative corrections to the decay of an unpolarized top quark into a bottom quark and a W gauge boson where the helicities of the W are specified as transverse-plus, transverse-minus and…
In supersymmetric theories, the top quark can decay into its scalar partner plus a neutralino, with an appreciable rate. We calculate the $O(\alpha_s)$ QCD corrections to this decay mode in the minimal supersymmetric extension of the…
An importance of the detailed studies of the theoretical QCD predictions for the decay width of Standard Model Higgs boson into bottom quarks, in the case when $\rm{M_H\leq 2M_W}$, is emphasized. The effects of higher order perturbative QCD…
We calculate the two-loop QCD correction to the scalar quark contributions to the electroweak gauge-boson self-energies at zero momentum-transfer in the supersymmetric extension of the Standard Model. We then derive the $O(\alpha_s)$…
We give a more complete calculation of $b \to s\gamma $ decay in 2-Higgs doublet model, including leading log QCD corrections from $m_{top}$ to $M_W$ in addition to corrections from $M_{W}$ to $m_b$. The inclusive decay rate in the first…
We calculate the supersymmetric ${\cal O}(\alpha_s)$ QCD corrections to stop and sbottom decays into vector bosons within the Minimal Supersymmetric Standard Model. We give analytic formulae and perform a numerical analysis of these decays.…
We present the two-loop QED and QCD corrections to the $f\bar fH$ Yukawa coupling that are induced by the exchange of a virtual photon or gluon, respectively, with a heavy-fermion loop inserted. As an application, we study the corresponding…
We present the complete calculation of the top-quark decay width at next-to-next-to-leading order in QCD, including next-to-leading electroweak corrections as well as finite bottom quark mass and $W$ boson width effects. In particular, we…
In this paper, we calculate the decay widths and branching fractions for the decays $Z \to H+ \gamma$ up to ${\cal O}(\alpha_{s} v^2)$ accuracy within the framework of nonrelativistic QCD, where $H$ stands for the $S$-wave quarkonium…
We calculate the O(alpha_s) and O(alpha_W m_t^2/M_W^2) corrections to the production of a single top quark via the weak process q qbar -> t bbar at the Fermilab Tevatron and the CERN Large Hadron Collider. An accurate calculation of the…
We consider the decay of an intermediate mass Higgs boson into hadrons up to order O(\alpha_s^3). The results from the diagrams containing only light degrees of freedom were recently computed in a previous work by K.G. Ch. (Phys. Lett. B…
We present the first complete high-precision QCD corrections to the inclusive decay width $\mathrm{\Gamma}_t$, the $W$-helicity fractions $f_{\mathrm{L,R,0}}$ and semi-inclusive distributions for the top-quark decay process $t \rightarrow b…
The QCD-induced $W^\pm \gamma$ production channels in association with two jets are computed at next-to-leading order QCD accuracy. The W bosons decay leptonicly and full off-shell and finite width effects as well as spin correlations are…
QCD corrections to $b \to s \gamma$ decay in the two Higgs doublet model are calculated from the energy scale of top quark to that of bottom. The constraints on the two Higgs doublet model from the new experimental bounds of $b\to s\gamma$…
By means of a heavy-top-quark effective Lagrangian, we calculate the three-loop corrections of O(alpha_s^2 G_F M_t^2) to the H->bb-bar partial decay width of the standard-model Higgs boson with intermediate mass M_H<<2M_t. We take advantage…
Different methods for treating the results of higher-order perturbative QCD calculations of the decay width of the Standard Model Higgs boson into bottom quarks are discusssed. Special attention is paid to the analysis of the $M_H$…
We give a more complete calculation of $b \to s\gamma $ decay, including leading log QCD corrections from $m_{top}$ to $M_W$ in addition to corrections from $M_{W}$ to $m_b$. We have included the full set of dimension-6 operators and…
We compute the one-loop supersymmetric QCD quantum effects on the width $\Gamma (t\rightarrow W^{+}\, b)$ of the canonical main decay of the top quark within the framework of the MSSM. The corrections can be of either sign depending on…
The O(alpha_s) SUSY QCD corrections to the decays of the MSSM Higgs bosons into bottom quarks and squarks can be very large for large tan beta in the on--shell renormalization scheme. We improve the calculation by a careful choice of the…
We consider in detail various theoretical uncertainties of the perturbative predictions for the decay width of $H^0\rightarrow b\overline{b}$ process in the region $50\ GeV< M_H\leq 2M_W$. We calculate the order…