相关论文: A Closer Look at Perturbative Corrections in the b…
We estimate the two-loop perturbative corrections to zero-recoil matrix elements of the flavour-changing currents $\bar c\,\gamma^\mu b$ and $\bar c\,\gamma^\mu\gamma_5\,b$ by calculating the terms of order $n_f\,\alpha_s^2$ and…
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 present a new determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{\rm cb}|$ by using the three-loop perturbative QCD corrections for the $B\to D^{\ast}$ semi-leptonic decay. The decay width of $B\to D^{\ast}$ semi-leptonic…
The question of the uniqueness of the Brodsky--Lepage--Mackenzie procedure for fixing the renormalization scale in perturbative QCD is discussed. It is shown that the resulting finite order approximants are as ambiguous as the original…
I review the recent progress in computing inclusive B decay widths and spectra and its implications on the interpretation of measurements from the B factories. I discuss the inclusive charmless semileptonic decay, B -> X_u l nu, which…
We discuss order 1/m_b^4 and 1/m_b^5 corrections in inclusive semileptonic decay of a $B$ meson. We identify relevant hadronic matrix elements of dimension seven and eight and estimate them using the ground-state saturation approximation.…
We study the impact of third-order QCD corrections for several kinematic moments of the inclusive semileptonic $B$ decays, to first order in the $1/m_b$ expansion. We consider the first four moments of the charged-lepton energy $E_\ell$…
We discuss recent higher order calculations to properties of $B$ mesons. This includes next-to-next-to-leading order corrections to nonleptonic and next-to-next-to-next-to-leading order corrections to semileptonic $B$ meson decays. The…
We determine $|V_{cb}|$ from inclusive semileptonic B decays including resummation of supposedly large perturbative corrections, which originate from the running of the strong coupling. We argue that the low value of the BLM scale found…
Nonperturbative corrections up to $m_b^{-2}$ to the heavy lepton energy distributions are investigated in the inclusive semileptonic weak decays of heavy flavors in QCD. In the case of $B$-meson decays, for $b \ra u\tau\bnu$ transitions…
We extend previous computations of the second order QCD corrections to semileptonic b \to c inclusive transitions, to the case where the charged lepton in the final state is massive. This allows accurate description of b \to c \tau \bar…
Recent advances in improving extractions of |Vcb| and m_b from spectra of semileptonic inclusive B decay are reported. Results of a general moment analysis of the lepton energy spectrum and the hadronic invariant mass spectrum are…
Strong interactions are addressed in connection to extracting |V_{cb}| and determining heavy quark parameters. A comprehensive approach allows a robust analysis not relying on a 1/m_c expansion; a percent defendable accuracy in |V_{cb}|…
We have calculated the perturbative corrections to all the structure functions in the semileptonic decays of a heavy quark. Assuming an arbitrary gluon mass as a technical tool allowed to obtain in parallel all the BLM corrections. We…
Perturbative corrections of the order of $\alpha_s$ to inclusive double differential lepton distribution from $b$ quark decay are considered. A perturbative correction to the charged lepton energy spectrum has been calculated for an…
We present a detailed evaluation of the total semileptonic B meson width in terms of |V_{cb}| and heavy quark parameters (quark masses and the expectation values of local heavy quark operators). Special attention is given to perturbative…
Recent progress in calculating O(alpha_s^2) corrections to inclusive and exclusive semileptonic b-->c transitions is reviewed. The impact of these corrections on the |V_cb| determination from both inclusive and exclusive B decays is…
In any calculation in perturbative Quantum Chromodynamics (QCD) a choice needs to be made for the unphysical renormalisation scale, $\mu_R$. The Brodsky-Lepage-Mackenzie/Principle of Maximum Conformality (BLM/PMC) scale-setting procedure is…
We present a determination of $|V_{cb}|$ from semileptonic B decays that includes resummation of supposedly large perturbative corrections, originating from the running of the strong coupling. We argue that the low value of the BLM scale…
It is shown that large perturbative corrections found previously for semileptonic beauty and charm decays are associated with using inappropriate pole masses. The latter, in the perturbative expansion, suffer from the 1/m_Q infrared…