相关论文: Recent Advances in Semileptonic B Decays
We use operator product expansion and QCD light-cone sum rules to estimate the amplitude of the decay $B \to J/\psi K $ taking into account leading nonfactorizable contributions. The result is very similar to the estimate obtained earlier…
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…
We report the first observation of the charmless two-body mode $B^{\pm} \to \omega K^{\pm}$ decay, and a new measurement of the branching fraction for the $B^{\pm} \to \omega \pi^{\pm}$ decay. The measured branching fractions are ${\cal B}…
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…
Consequences of the interference between external and internal spectator amplitudes for the lifetimes and semileptonic decay fractions of $B^0$ and $B^+$ mesons are discussed. Extrapolating from the constructive interference observed in 11…
Quark-hadron duality in the inclusive semileptonic decay $B\to X_c l\nu$ in the Shifman-Voloshin limit $\Lambda \ll \delta m=m_b - m_c \ll m_b, m_c$ is studied within a nonrelativistic potential model. The integrated semileptonic decay rate…
With the experimental evidences of $\overline B {}^0\to p \overline{p}$ and $B^-\to\Lambda\overline p$ decays, it is now possible to extract both tree and penguin amplitudes of the charmless two-body baryonic $B$ decays for the first time.…
Semileptonic decays of charged and neutral $B$ mesons play a critical role in the determination of the magnitudes of the CKM-matrix elements $V_{cb}$ and $V_{ub}$, and in the test of the lepton universality which is a basic assumption of…
Semileptonic and nonleptonic decays of the B_c meson to B_s and B mesons, caused by the c\to s,d quark transitions, are studied in the framework of the relativistic quark model. The heavy quark expansion in inverse powers of the active c…
We reconsider the prediction of the semileptonic branching ratio of B mesons, using a recent calculation of the radiative corrections with account for finite quark masses in nonleptonic decays and taking into account 1/m_b^2 corrections.…
Recent experimental searches for $A_{SL}$, the CP asymmetry in semileptonic B decay, have reached an accuracy of order one percent. Consequently, they give meaningful constraints on new physics. We find that cancellations between the…
Recent analyses of the LEP and Upsilon(4S) data have better outlined the picture of semileptonic B decays. Results on inclusive and exclusive decay branching fractions and on the extraction of the |Vub| and |Vcb| elements of the CKM mixing…
Recent experimental measurements and lattice QCD calculations are now reaching the precision (and accuracy) needed to over-constrain the CKM parameters $\bar\rho$ and $\bar\eta$. In this brief review, I discuss the current status of lattice…
The form factors of weak decays of the B_c meson to orbitally excited charmonium, D, B_s and B mesons are calculated in the framework of the QCD-motivated relativistic quark model based on the quasipotential approach. Relativistic effects…
We calculate nonperturbative ${\cal O}(\Lambda^2_{QCD}/m^2_c)$ corrections to the dilepton invariant mass spectrum and the forward-backward charge asymmetry in $B\to X_se^+e^-$ decay using a heavy quark expansion approach. The method has…
The differential decay spectrum $d\Gamma/dE_e dq^2$ for the semileptonic decay of an unpolarized hadron containing a b-quark, and the decay spectrum $d\Gamma/dE_e dq^2 d\!\cos\theta$ for polarized $\Lambda_b$ decay are computed to second…
Non-perturbative effects have a small but non-trivial impact on the determination of the strong coupling from hadronic $\tau$ decay data. Several approaches have been proposed to take these into account, the two most important of which are…
In this mini-review, we show that a lot of theoretical efforts have been made for the theoretical study of two body hadronic $B_{(s)}$ and $B_c$ decays. In addition to many next-to-leading order or even next-to-next-to leading order…
We update the Standard Model (SM) predictions for the lifetimes of the $B^+$, $B_d$ and $B_s$ mesons within the heavy quark expansion (HQE), including the recently determined NNLO-QCD corrections to non-leptonic decays of the free…
We comment on two recent calculations of the second order perturbative corrections in the heavy flavor semileptonic transitions within the Brodsky-Lepage-Mackenzie approach. It is pointed out that the results do not show significant…