QCD Calculations of Decays of Heavy Flavor Hadrons

Matthias Neubert

Published 2008-01-04Version 1

Precision tests of the Standard Model and searches for New Physics in the quark flavor sector depend on accurate theoretical calculations of decay rates and spectra for rare, flavor-changing processes. The theoretical status and recent developments of techniques allowing such calculations are reviewed. Special attention is paid to the calculation of the B->Xs+gamma branching ratio, the extraction of the b-quark mass from a fit to B->Xc+l+nu moments, and the determination of |V(ub)| from spectra in the inclusive decay B->Xu+l+nu. From a reanalysis of different inclusive distributions the updated average value |V(ub)|=(3.98+-0.15+-0.30)*10^{-3} is derived. Using only the theoretically cleanest channels, we obtain |V(ub)|=(3.70+-0.15+-0.28)*10^{-3}.