Next-to-leading order QCD corrections to the lifetime difference of Bs mesons

We compute the QCD corrections to the decay rate difference in the B-s-(B) over bar(s) system, Delta Gamma(Bs), in the next-to-leading logarithmic approximation using the heavy quark expansion approach. Going beyond leading order in QCD is essential to obtain a proper matching of the Wilson coefficients to the matrix elements of local operators from lattice gauge theory. The lifetime difference is reduced considerably at next-to-leading order. We find (Delta Gamma/Gamma)(Bs) = (f(Bs)/210 MeV)(2)[0.006B(m(b)) + 0.150 B-S(m(b)) - 0.063] in terms of the bag parameters B, B-S in the NDR scheme. As a further application of our analysis we also derive the next-to-leading order result for the mixing-induced CP asymmetry in inclusive b --> u (u) over bar d decays, which dmeasures sin2 alpha. (C) 1999 Published by Elsevier Science B.V. All rights reserved.