Related papers: Towards two- and three-loop QCD corrections to the…
In this talk we present a calculation of the dacay rate difference in the neutral $B_s-\bar{B}_s$ system, $\Delta \Gamma_{B_s}$, in next-to-leading order (NLO) QCD. We find a sizeable decrease compared to leading-order (LO) estimates: $…
We discuss the determination of the strong coupling $\alpha_\mathrm{\overline{MS}}^{}(m_\mathrm{Z})$ or equivalently the QCD $\Lambda$-parameter. Its determination requires the use of perturbation theory in $\alpha_s(\mu)$ in some scheme,…
We compute the order alpha_s^3 (next-to-leading) corrections to the Wilson coefficients of the Delta F=2 effective Hamiltonian in the Minimal Supersymmetric Standard Model with completely arbitrary soft terms. These results are relevant for…
The present status of the theoretical estimates of the difference between the widths of the neutral Bs-mesons and of the B-meson lifetime ratios is reviewed. In particular, the lattice results for the matrix elements of the relevant (delta…
We present new contributions to the decay matrix element $\Gamma_{12}^q$ of the $B_q$-$\bar B_q$ mixing complex, where $q=d$ or $s$. Our new results constitute the order $\alpha_s^2 N_f$ corrections to the penguin contributions to the…
Current status of the NNLO QCD corrections to B -> X_s gamma is reviewed. The calculations include three-loop matching conditions, four-loop anomalous dimensions as well as two- and three-loop on-shell amplitudes. Certain parts of the…
Theoretical predictions for the $D^0\overline{D^0}$ mixing parameters fall significantly short of experimental measurements, with discrepancies spanning several orders of magnitude. This gap is mainly due to the Glashow-Iliopoulos-Maiani…
We update the Standard-Model predictions for several quantities related to $B_s - \bar B_s$ and $B_d - \bar B_d$ mixing. The mass and width differences in the $B_s$ system read $ \Delta M_s^{\rm SM} = (17.3 \pm 2.6) ps^{-1}$ and $\Delta…
We estimate \Delta Gamma_d/\Gamma_d, including 1/m_b contributions and part of the next-to-leading order QCD corrections, and find it to be around 0.3%. We show the methods to measure \Delta Gamma_d/\Gamma_d by using at least two different…
We observe that quantities like (f_{B_s}/f_B) / (f_{D_s} /f_D) are predicted to be unity both by heavy quark and by light quark flavor symmetries. Hence, the deviation from the symmetry prediction must be simultaneously small in both…
The decay width of $Z^0$ to $B_c$ meson is evaluated at the next-to-leading order(NLO) accuracy in strong interaction. Numerical calculation shows that the NLO correction to this process is remarkable. The quantum…
Global fits for precision determinations of parton distributions, together with the highly correlated strong coupling $\alpha_s$, are presented up to next-to-next-to-leading order (NNLO) of QCD utilizing most world data (charm and jet…
Recent results relevant for the B-physics phenomenology, obtained from lattice QCD simulations by the APE Collaboration, are reviewed. This includes the B0-B0bar mixing amplitude, B-> pi semileptonic decay and the relative width difference…
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 present the QCD corrections to the matching conditions of the Delta B =1 magnetic and chromo-magnetic operators in the Standard Model and in two-Higgs doublet models. We use an off-shell matching procedure which allows us to perform the…
We present the first complete order alpha_s corrections to the Wilson coefficients (at the high scale) of the various versions of magnetic and chromomagnetic operators which are induced by a squark-gluino exchange. For this matching…
The recent measurements of the $B_s$ mass difference $\Delta M_s$ by the CDF and D{\O} collaborations are roughly consistent with the Standard Model predictions, therefore, these measurements will afford an opportunity to constrain new…
We determine the uncertainty on the strong coupling alpha_S due to the experimental errors on the data fitted in global analysis of hard-scattering data, within the standard framework of leading-twist fixed-order collinear factorisation in…
We present the NLO corrections to the Wilson coefficients of the Delta F = 2 Hamiltonians in the strong interacting sector of the MSSM, responsible for neutral meson oscillations. Such corrections, combined with the NLO anomalous dimension…
The order $\alpha_s$ corrections to the Wilson coefficients of the dipole operators ($O_7,O_8$) at the matching scale $\mu =m_W$ are a crucial ingredient for a complete next- to-leading logarithmic calculation of the branching ratio for $b…