相关论文: Two-Loop Relations for Heavy-Quark Parameters in t…
The shape function of $B$-meson defined in heavy quark effective theory (HQET) plays a crucial role in the analysis of inclusive $B$ decays, and constitutes one of the dominant uncertainties in the determination of CKM matrix element…
The values of two important parameters of the heavy quark effective theory,\, $\bar \Lambda$ and $\mu_\pi^2$ (the mean value of the heavy quark three momentum squared),\, have been determined recently in \cite {GKLW} from the precise CLEO…
We consider HQET including the first order correction in 1/m. A strategy for the computation of the b-quark mass is discussed. Only two quantities Phi_1/2 have to be considered in order to match QCD and HQET, since the spin-dependent…
We compute the mass of the b-quark and the B_s meson decay constant in quenched lattice QCD using a combination of HQET and the standard relativistic QCD Lagrangian. We start from a small volume, where one can directly deal with the…
B meson semileptonic decays are a crucial tool in our studies of the quark mixing parameters Vcb and Vub. The interplay between experimental and theoretical challenges to achieve precision in the determination of these fundamental…
We consider electroweak corrections to the relation between the running $\overline{\mathrm{MS}}$ mass $m_b$ of the $b$ quark in the five-flavor QCD$\times$QED effective theory and its counterpart in the Standard Model (SM). As a bridge…
Masses and decay constants of mesons containing a single $c$ or $b$ quark are described within the framework of heavy-quark symmetry. The $B_s^* - B_s$ and $\bar B^{*0} - \bar B^0$ mass splittings are found equal to within a fraction of an…
We derive the strange quark transverse momentum distribution for the $% b\to s\gamma $ decay. A resummed formula is presented showing the singularity structure in the impact parameter $b$. We observe the appearance of a new next-to-leading…
The important parameter \mu_G^2 of the heavy quark expansion is analyzed including perturbative and power corrections. It is found that \mu_G^2(2GeV) is known with a few percent accuracy. The perturbative corrections are computed and found…
The moments of the heavy quark-parton distribution functions in a heavy pseudoscalar meson are calculated from QCD sum rules. Expanding these sum rules in the inverse heavy quark mass we obtain the heavy-mass limits of the moments.…
The interaction potential V(Q^2) between static test charges can be used to define an effective charge $\alpha_V(Q^2)$ and a physically-based renormalization scheme for quantum chromodynamics and other gauge theories. In this paper we use…
We point out that applying the photon energy cut significantly modifies the moments of energy spectrum in B->X_s+gamma decays, with a certain class of effects not accounted for in the mostly used OPE expressions. This leads to a systematic…
Exploiting recently proposed novel improvements of the techniques used for extracting from QCD sum rules pivotal hadron characteristics, including their systematic errors, we succeed to achieve a conspicuous agreement of the predictions of…
We compute the exact two-loop matching coefficients for the strong coupling constant alpha_s and the bottom-quark mass m_b within the Minimal Supersymmetric Standard Model (MSSM), taking into account O(alpha_s^2) contributions from…
We measured two moments of the lepton momentum spectrum in B -> X l nu, where l= e or mu, for p_l > 1.5 GeV/c. From these we derive the Heavy Quark Expansion (HQE) parameters Lambda-bar(MS-bar) = 0.39 +- 0.03(stat) +- 0.06(sys) +- 0.12(th)…
The contributions of subleading shape functions to inclusive decay distributions of B mesons are derived from a systematic two-step matching of QCD current correlators onto soft-collinear and heavy-quark effective theory. At tree-level, the…
The fully heavy axial-vector diquark-antidiquark structures $bb\overline{c} \overline{c}$ are explored by means of the QCD sum rule method. They are modeled as four-quark mesons $T_{\mathrm{1}}$ and $T_{\mathrm{2}}$ composed of…
B meson rare decays ($B\to K(K^{*})l\bar l$ and $B\to K^*\gamma$) are analyzed in the framework of effective field theory of heavy quarks. The semileptonic and penguin type form factors for these decays are calculated by using the light…
Precision determinations of the top-quark mass require theory predictions with a well-defined mass parameter in a given renormalization scheme. The top-quark's running mass in the MSbar scheme can be extracted with good precision from the…
The comparison between parameterisations of the perturbation results for the decay width of the Standard Model Higgs boson to \bar{b}b-quarks pairs, based on application of \bar{MS}-scheme running quark mass and pole b-quark mass, are…