  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). Large corrections to these predictions come from
phase-space enhanced 1/mb^3 contributions, i.e. hard spectator effects. In this
paper we calculate the next-to-leading order QCD corrections to the Wilson
coefficients of the local operators appearing at O(1/mb^3). We find that these
corrections improve the agreement with the experimental data. The lifetime
ratio of charged to neutral B mesons, tau(B+)/tau(Bd), turns out to be in very
good agreement with the corresponding measurement, whereas for tau(Bs)/tau(Bd)
and tau(Lambdab)/tau(Bd) there is a residual difference at the 1-sigma level.
We discuss, however, why the theoretical predictions are less accurate in the
latter cases.
