The calculation of QCD corrections to the width difference Delta Gamma in the
B_s meson system is presented. The next-to-leading order corrections reduce the
dependence on the renormalization scale significantly and allow for a
meaningful use of hadronic matrix elements from lattice gauge theory. At
present the uncertainty of the lattice calculations limits the prediction of
Delta Gamma. The presented work has been performed in collaboration with Martin
Beneke, Gerhard Buchalla, Christoph Greub and Alexander Lenz.Comment: Talk at "4th Workshop on Continuous Advances in QCD," 12-14 May 2000,
Minneapolis, Minnesota, US
