相关论文: Next-to-next-to-leading QCD corrections to the $\m…
The lifetime splitting between the B^+ and B_d^0 mesons has recently been calculated in the next-to-leading order of QCD. These corrections are necessary for a reliable theoretical prediction, in particular for the meaningful use of…
We describe a theoretical approach to compute inclusive widths of heavy hadrons, based on a systematic expansion in the inverse powers of the heavy quark mass. The method reproduces quite well the experimental ratios of $B$ mesons…
We compute next-to-leading order QCD corrections to the $1/m_b^2$ terms of the Heavy Quark Expansion for the contribution to inclusive nonleptonic bottom hadron decays induced by the charged-current operators mediating the transitions $b…
We compute perturbative QCD corrections to the lifetime splitting between the charged and neutral $B$ meson in the framework of the heavy quark expansion. These next-to-leading logarithmic corrections are necessary for a meaningful use of…
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 present some straightforward applications of the QCD heavy quark expansion, stated in previous papers [1-3], to the inclusive widths of heavy flavour hadrons. We address the question of the $D_s$ lifetime and argue that -- barring Weak…
Lifetime differences of heavy hadrons can be consistently computed in heavy-quark expansion. The leading effects appear through spectator interactions at order 1/m_b^3. We compute a well-defined subset of 1/m_b^4 corrections to the lifetime…
Using the expansions of the heavy meson decay widths in the heavy quark mass and QCD sum rules for estimates of corresponding matrix elements,\, we calculate the $D^{\pm,o,s}$ decay widths and the $B^{\pm,o,s}$ lifetime differences. The…
We review current status of theoretical predictions of lifetimes of heavy hadrons in heavy-quark expansion. We present a calculation of subleading 1/m_b corrections to spectator effects in the ratios of beauty hadron lifetimes. We find that…
We develop perturbative QCD factorization theorems for inclusive b-hadron decays, in which radiative corrections characterized by the hadronic scale, the b-hadron mass, and the W boson mass are absorbed into a heavy hadron distribution…
This paper presents $\alpha_s$ corrections to the inclusive semitauonic $B \to X_c \tau \bar{\nu}_\tau$ decay width and leptonic invariant mass spectrum up to order $1/m_b^3$ in the heavy quark expansion. Analytical results with full…
We study the lifetimes and inclusive semileptonic decay widths of doubly heavy baryons within the framework of heavy quark expansion. Our analysis includes next-to-leading-order corrections to the dimension-3, -5, and -6 operators, together…
Theoretical predictions of beauty hadron lifetimes, based on the heavy quark expansion up to and including order 1/mb^2, do not to reproduce the experimental measurements of the lifetime ratios tau(B+)/tau(Bd) and tau(Lambdab)/tau(Bd).…
We present a calculation of subleading 1/m_b corrections to spectator effects in the ratios of beauty hadron lifetimes in heavy-quark expansion. We find that these effects are sizable and should be taken into account in systematic analyses…
The QCD-based operator-product-expansion technique is systematically applied to the study of charmed meson lifetimes. We stress that it is crucial to take into account the momentum of the spectator light quark of charmed mesons, otherwise…
Determining for the first time the Darwin operator contribution for the non-leptonic charm-quark decays and using new non-perturbative results for the matrix elements of $\Delta C=0$ four-quark operators, including eye-contractions, we…
The B meson lifetime ratios are calculated to the order of $1/m_b^3$ in the heavy quark expansion. The predictions of those ratios are dependent on four unknown hadronic parameters $B_1$, $B_2$, $\epsilon_1$ and $\epsilon_2$, where $B_1$…
A phenomenological analysis of lifetimes of bottom and charmed hadrons within the framework of the heavy quark expansion is performed. The baryon matrix element is evaluated using the bag model and the nonrelativistic quark model. We find…
We compute the next-to-leading order QCD corrections to spectator effects in the lifetime ratios of beauty hadrons. With respect to previous calculations, we take into account the non vanishing value of the charm quark mass. We obtain the…
In this note radiative corrections to the total hadronic decay rate of the $\tau$-lepton are studied employing perturbative QCD and the operator product expansion. We calculate quadratic quark mass corrections to the decay rate ration…