相关论文: QCD Corrections to $b \to s e^+e^-$ Decay

We analyse subleading electroweak effects in the top anti-top resonance production region in e+ e- collisions which arise due to the decay of the top and anti-top quarks into the W+ W- b bbar final state. These are NLO corrections adopting…

In this paper the complete two-loop corrections to the Higgs-boson decay, H -> gamma gamma, are presented. The evaluations of both QCD and electroweak corrections are based on a numerical approach. The results cover all kinematical regions,…

The matrix element of the weak transition {\Lambda}_b\rightarrow{\Lambda}_c can be expressed in terms of six form factors. {\Lambda}_Q(Q = b;c) can be regarded as composed of a heavy quark Q(Q = b;c) and a diquark which is made up of the…

We revise the radiative corrections to double-Dalitz decays ($P\to\ell\bar{\ell}\ell'\bar{\ell}'$), completing the full next-to-leading order calculation in QED as compared to existing calculations. As a result, we find mild differences…

Theoretical predictions for the decay width of Standard Model Higgs boson into bottom quarks and tau-leptons, in the case when M_H< 2M_W, are briefly reviewed. The effects of higher order perturbative QCD (up to alpha_s^4-level) and QED…

In this note radiative corrections to the total hadronic decay rate of the $\tau$-lepton are studied employing perturbative QCD and the operator product expansion. We calculate quadratic quark mass corrections to the decay rate ration…

We present $O(\alpha_s^2)$ QCD corrections to the fully-differential decay rate of a $b$-quark into inclusive semileptonic charmless final states. Our calculation provides genuine two-loop QCD corrections, beyond the…

We study the effects of QCD corrections to the process $e^+e^-\rightarrow t\bar t+X\rightarrow b\ell^+\nu \bar b\ell^-\bar \nu+X$ above threshold. We show how to treat consistently to ${\cal O}(\alpha_s)$ the gluon radiation in both the…

QCD radiative correction to Higgs $\rightarrow$ two photons decay rate is calculated. Below the threshold we found negligible correction, thus supporting results obtained earlier by Djouadi et all [7]. Above the threshold radiative…

We discuss the supersymmetric O(alpha_s) QCD corrections to e+ e- -> squark_i + antisquark_j (i,j = 1,2) and to squark_i -> q' + chargino_j, q + neutralino_k (i,j = 1,2; k = 1...4) within the Minimal Supersymmetric Standard Model. In…

In this article we calculate the 1-loop supersymmetric QCD (SQCD) corrections to the decay $\tilde u_1\to c \tilde\chi^0_1$ in the MSSM with generic flavour structure. This decay mode is phenomenologically important if the mass difference…

We discuss the computation of QCD virtual corrections to the top production and decay process at linear colliders. The double pole approximation (DPA) is used, and we comment on similarities and differences between our results and results…

We study the form factor f_+^H (H=D,B) involved in H-\pi transitions. We use data on D^0 \to \pi^- l^+ \nu to find f_+^D at low recoil. Then we use perturbative QCD methods to calculate at larger recoil the contributions to f_+^H that break…

We investigate electromagnetic corrections to the rare $B$-meson leptonic decay $B_{s,d} \to \mu^+\mu^-$ from scales below the bottom-quark mass $m_b$. Contrary to QCD effects, which are entirely contained in the $B$-meson decay constant,…

The rare decays $B^0 \to D_s^- K^+$ and $B^+ \to D_s^+ \bar{K}^0$ can occur only via annihilation type diagrams in the standard model. We calculate these decays in perturbative QCD approach. We found that the calculated branching ratio of…

In this dissertation, a complete calculation of QED radiative corrections is presented for total cross sections and forward- backward asymmetries for s-channel fermion pair production in e+e- annihilation with kinematical cuts to the final…

If tan beta is large, supersymmetric QCD corrections can become large, putting naive perturbation theory into doubt. I show how these tan-beta-enhanced corrections can be controlled to all orders in alpha_s tanbeta. The result is shown for…

We summarize recent results on QCD corrections to various observables in semileptonic $b$ quark decays. For massless leptons in the final state we present effects of such corrections on triple differential distribution of leptons which are…

We investigate the $B \to K^{*}\pi$ decays, one of hardly understandable processes among charmless B-meson decays, within the perturbative QCD method. Owing to the dynamically enhanced mechanism in PQCD, we obtain large branching ratios and…

We propose a method for a QCD based calculation of one-particle inclusive decays of the form B \to \bar D X or B \to \bar D^* X. It is based on the heavy mass limit and a short distance expansion of the amplitudes, which yield a power…