Lifetime ratios of beauty hadrons at the next-to-leading order in QCD Original Research Article

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 predictions τ(B+)/τ(Bd)=1.06±0.02, τ(Bs)/τ(Bd)=1.00±0.01 and τ(Λb)/τ(Bd)=0.90±0.05, in good agreement with the experimental results. In the case of τ(Bs)/τ(Bd) and τ(Λb)/τ(Bd), however, some contributions, which either vanish in the vacuum insertion approximation or represent a pure NLO correction, have not been determined yet.