相关论文: Lifetimes of heavy hadrons
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…
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…
I discuss the heavy quark expansion for the inclusive widths of heavy-light hadrons, which predicts quite well the experimental ratios of B_q meson lifetimes. As for $\Lambda_b$, current determinations of ${\cal O}(m_b^{-3})$ contribution…
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 provide updated predictions of the lifetimes of singly charmed baryons and mesons within the heavy quark expansion, with all known corrections included. A special attention is devoted to the choice of the charm mass and wavefunctions of…
The status of heavy quark expansions for charm and beauty lifetime ratios is reviewed. Taking note of the surprising semiquantitative success of this description for charm hadrons I interprete the new data on $\tau (D_s)$ and re-iterate the…
The lifetimes of bottom and charmed hadrons are analyzed within the framework of the heavy quark expansion (HQE). Lifetime differences arise from the spectator effects such as weak $W$-annihilation and Pauli interference. Spectator effects…
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 $B_1$…
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).…
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 discuss two problems in the theory of heavy-quark decays: an understanding of the semileptonic branching ratio of $B$ mesons, and of the lifetime ratio $\tau(\Lambda_b)/\tau(B^0)$. We also present a model-independent study of spectator…
We present updated predictions for lifetimes of doubly charmed baryons, within the heavy quark expansion, including available NLO $\alpha_s$ contributions and newly-computed terms in the $1/m_c$ series. Our improved results confirm the…
Inclusive heavy-flavour decays can be described through $1/m_Q$ expansions derived from QCD with the help of an operator product expansion. I sketch their methodology and apply them first to semileptonic B decays; $|V(cb)|$ can be extracted…
In the 1990s, very low experimental values for the lifetime ratio $\tau (\Lambda_b)/\tau(B_d)$ triggered a considerable amount of doubt in the applicability of the heavy quark expansion (HQE), which is based on the assumption of…
A critical review of the theoretical understanding of the lifetimes of beauty hadrons is given. A model-independent analysis using the heavy-quark expansion allows for a description of the lifetime ratios tau(B-)/tau(B0) and…
We present the theoretical status of the lifetimes of weakly decaying heavy hadrons containing a bottom or a charm quark, and discuss the current predictions, based on the framework of the Heavy Quark Expansion (HQE), for both mesons and…
We provide an extensive study of the lifetimes of singly charmed baryons and mesons, within the heavy quark expansion with all known corrections included. A special attention is devoted to the choice of the charm mass and wavefunctions of…
We evaluate the matrix elements of the four-quark operators which contribute to the lifetimes of $B$-mesons and the $\Lambda_b$-baryon. We find that the spectator effects are not responsible for the discrepancy between the theoretical…
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…