Next-to-leading order QCD corrections to spectator effects in lifetimes of beauty hadrons

Theoretical predictions of beauty hadron lifetimes, based on the heavy quark expansion up to and including order 1/m(b)(2) do not to reproduce the experimental measurements of the lifetime ratios tau (B+) /tau (B-d) and tau (Lambda(b)) /tau (B-d). Large corrections to these predictions come from phasespace enhanced 1/m(b)(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/m(b)(3)). We find that these corrections improve the agreement with the experimental data. The O(1/m(b)(3)) lifetime ratio of charged to neutral B-mesons, tau (B+) /tau (B-d), turns out to be in very good agreement with the corresponding measurement, whereas for tau (B-s) /tau (B-d) and tau (Lambda(b)) /tau (B-d) there is a residual difference at the 1sigma level. We discuss, however, why the theoretical predictions are less accurate in the latter cases.