Enhancement of preasymptotic effects in inclusive beauty decays

We extend Voloshinʹs recent analysis of charmed and beauty hyperon decays based on SU(3) symmetry and heavy quark effective theory, by introducing a rather moderate model-dependence, in order to obtain more predictive power, e.g. the values of lifetimes of the (Λb,Ξb) hyperon triplet and the lifetime of Ωb. In this way we obtain an improvement of the ratio τ(Λb)/τ(Bd0)∼0.9 and the hierarchy of lifetimes τ(Λb)≃τ(Ξb0)<τ(Ξb−)<τ(Ωb) with lifetimes of Ξb− and Ωb exceeding the lifetime of Λb by 22% and 35%, respectively.