Related papers: B decay shape variables and the precision determin…
In light of the large amount of new experimental data, we revisit the determination of V_{cb} and m_b from inclusive semileptonic and radiative B decays. We study shape variables to order lqcd^3/m_b^3 and alpha_s^2\beta_0, and include the…
The spectra and form factors of exclusive semi-leptonic decays of B-meson are analyzed, taking account of confined effects of quarks by the Covariant Oscillator Quark Model. The predicted B --> (D*,D)l nubar_l spectra with the conventional…
Recently we studied the B, Bs, D and Ds meson decay constants using various treatments for the heavy quark. For B mesons, we determined fB, fBs, and fBs/fB with NRQCD bottom quarks. We then combined the ratio fBs/fB and another very precise…
We report on the determination of $|V_{cb}|$ from the comparison of the semileptonic inclusive decay rates of B-- and D--mesons using the heavy quark symmetry of QCD. While the renormalization scale ambiguity does not allow for a reliable…
The more precise extraction for the CKM matrix element |V_{cb}| in the heavy quark effective field theory (HQEFT) of QCD is studied from both exclusive and inclusive semileptonic B decays. The values of relevant nonperturbative parameters…
Precision tests of the CKM mechanism and searches for new physics in the flavour sector require dedicated QCD calculations of decay widths and spectra. Significant progress has been achieved in recent years in computing inclusive B decay…
We present a fit to measured moments of inclusive distributions in B->Xc lv and B-> Xs gamma decays to extract values for the CKM matrix element |Vcb|, the b- and c-quark masses, and higher order parameters that appear in the Heavy Quark…
Measurements of many Standard Model constants are clouded by uncertainties in nonperturbative QCD parameters that relate measurable quantities to the underlying parton-level processes. Generally these QCD parameters have been obtained from…
We present a precise lattice QCD determination of the b-quark mass, of the B and Bs decay constants and first results for the B-meson bag parameters. For our computation we employ the so-called ratio method and our results benefit from 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…
Aspects of the OPE-based QCD theory of B decays are discussed. We have at least one nontrivial precision check of the OPE at the nonperturbative level in inclusive decays. The data suggest proximity to the `BPS' limit for B mesons. Its…
We propose determining |V_{ub}| from inclusive semileptonic B decay using combined cuts on the leptonic and hadronic invariant masses to eliminate the b->c background. Compared to a pure dilepton invariant mass cut, the uncertainty from…
We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ times the form factor normalization $\mathcal{F}(1)$ using the decay $B^+\to\bar D^{*0}\ell^+\nu_\ell$. This measurement is performed together with a…
This article describes a determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ from the decay $B^0\to D^{*-}\ell^+\nu_\ell$ using 711 fb$^{-1}$ of Belle data collected near the $\Upsilon(4S)$ resonance. We simultaneously…
In order to determine the ratio of CKM matrix elements |V_{ub}/V_{cb}| (and |V_{ub}|), we propose a new model-independent method based on the heavy quark effective theory, which is theoretically described by the phase space factor and the…
Theoretical predictions for inclusive semileptonic B decay rates are rewritten in terms of the Upsilon(1S) meson mass instead of the b quark mass, using a modified perturbation expansion. This method gives theoretically consistent and…
We present precise lattice computations for the b-quark mass, the quark mass ratios mb/mc and mb/ms as well as the leptonic B-decay constants. We employ gauge configurations with four dynamical quark flavors, up/down, strange and charm, at…
We extract the magnitude of the CKM matrix element Vcb and the most relevant parameters of the Heavy Quark Expansion from data of inclusive semileptonic B decays. Our calculation includes the recently computed O(alphas Lambda^2/mb^2)…
We extract the Cabibbo-Kobayashi-Maskawa matrix element $V_{cb}$ from the exclusive decays of $\Lambda_b\to \Lambda_c\ell\bar \nu_\ell$ and $\Lambda_b\to \Lambda_c M_{(c)}$ with $M=(\pi^-,K^-)$ and $M_c=(D^-,D^-_s)$, where the branching…
We report a measurement of the branching fractions for $B^{0} \rightarrow \pi^- \ell^+\nu$ and $B^{0} \rightarrow \rho^-\ell^+\nu$ decays, using charged and neutral $B$ decays with isospin constraints. We find ${\cal B}(B^{0} \rightarrow…