Related papers: Second Order QCD Corrections to the Top Decay Rate
We analyze the relativistic corrections to annihilation rates of S-wave quarkonia within the framework of NRQCD. We show that order v^2 corrections can be expressed in terms of the heavy quark pole mass and the quarkonium mass. The ratio of…
We calculate the branching ratios and CP asymmetries of the $B \to \pi \rho$, $\pi\omega $ decays in the perturbative QCD factorization approach up to the next-to-leading-order contributions. We find that the next-to-leading-order…
We present in analytic form the O(alpha_s^5) correction to the H->gg partial width of the standard-model Higgs boson with intermediate mass M_H<2M_t. Its knowledge is useful because the O(alpha_s^4) correction is sizeable (around 20%). For…
We calculate next to leading order QCD corrections to the direct decays b -> J/Psi + X and b -> eta_c + X. The strong renormalization scale dependence is seen to persist also in this order and in fact the rate is driven to an unphysical…
We describe a first-principles method to apply lattice QCD to compute the order $\alpha_{\mathrm{EM}}$ corrections to $K\to\pi\ell\nu_\ell$ decay. This method formulates the calculation in infinite volume with the conventional…
We report on the computation of the $B_s$ meson decay constant in Heavy Quark Effective Theory on the lattice. The next to leading order corrections in the HQET expansion are included non-perturbatively. We estimate higher order…
The standard approaches for describing top quark production and its decay dynamics are currently mostly either based on the narrow-width (NW) limit or on off-shell fixed-order calculations. In this article we present a factorised approach…
In this article, we study in detail the double-$J/\psi$ yield through $Z$ decay at the next-to-leading-order (NLO) QCD accuracy within the nonrelativistic QCD factorization. At the tree level, the pure QCD diagrams predict a branching ratio…
The production of top-antitop-quark pairs at hadron colliders is interesting both in its own right as signal process, but also as background to many searches for new physics. The corresponding predictions aim at the precision level of few…
We review recent results on next-to-leading order (NLO) QCD and electroweak (EW) corrections for processes involving off-shell top quarks. For the off-shell production of two top quarks that decay leptonically, the full NLO EW corrections…
Top quark mass suppressed terms are calculated for the virtual amplitude for Higgs production in gluon fusion at three-loop level, i.e. O(\alpha_s^3). The method of asymptotic expansions in its automated form is used to evaluate the first…
We calculate the $\mathcal{O}(\alpha_s)$ QCD corrections to the inclusive $h\to b\bar b$ decay rate in the dimension-6 Standard Model Effective Field Theory (SMEFT). The QCD corrections multiplying the dimension-6 Wilson coefficients which…
We find the effective neutral current in the heavy top quark limit up to and including the terms of order $\alpha_s^3$. The result is then employed to compute the correction of the same order to the axial part of the Z decay rate into…
We calculate the $O(\alpha_s)$ corrections to the charged Higgs mediated inclusive semi-tauonic $B$ decay. By working in the Landau gauge, we demonstrate how to obtain the charged Higgs contributions (both direct and interference terms)…
We have calculated the next-to-leading order perturbative QCD corrections to the photon energy spectrum in radiative Upsilon decays. The higher-order corrections significantly modify the shape of the spectrum, in particular at large photon…
Radiative corrections in the order ${\alpha\over{2\pi}}{{m^2_e}\over m^2_\mu}$ to $\mu $- and ${\alpha\over{2\pi}}{{m^2_\mu}\over m^2_\tau}$ to $\tau $- decays are calculated. The decay width is enhanced by $4.48\cdot 10^{-3}…
We calculate the next-to-next-to-leading-order (NNLO) perturbative corrections to $P$-wave quarkonia annihilation decay to two photons, in the framework of nonrelativistic QCD (NRQCD) factorization. The order-$\alpha_s^2$ short-distance…
We report on the calculation of the next-lo-leading order QCD corrections to Higgs boson production and decay in association with top quarks. We consider leptonic decays of top quarks leading to the hadronic process $pp\to e^+\nu_e\,…
We present the higher order QCD corrections to the fragmentation functions and the corresponding cross sections.
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.…