Charm Quark Mass Dependence of QCD Corrections to Nonleptonic Inclusive B Decays

We calculate the radiative corrections to the nonleptonic inclusive B decay mode b → cūd taking into account the charm quark mass. Compared to the massless case, corrections resulting from a nonvanishing c quark mass increase the nonleptonic rate by (4–8)%, depending on the renormalization point. As a by–product of our calculation, we obtain an analytic expression for the radiative correction to the semileptonic decay b → uτν̄ taking into account the τ lepton mass, and estimate the c quark mass effects on the nonleptonic decay mode b → cc̄s. To appear in Nucl. Phys. B Permanent address: Grup de F́ısica Teòrica, Dept. de F́ısica and Institut de F́ısica d’Altes Energies, IFAE, Universitat Autònoma de Barcelona, E–08193 Bellaterra (Barcelona), Spain Address after September 1994: CERN, Theory Division, CH–1211 Genève 23, Switzerland Address after August 1994: DESY, Notkestraße 85, D–22603 Hamburg, Germany