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 --> c(u) over bard$ taking into account the charm quark m ass. Compared to the massless case, corrections resulting from a nonva nishing c quark mass increase the nonleptonic rate by (4-8)%, dependin g on the renormalization point. As a by-product of our calculation, we obtain an analytic expression for the radiative correction to the sem ileptonic decay b --> <u tau(v)over bar> taking into account the tau l epton mass, and estimate the c quark mass effects on the nonleptonic d ecay mode b --> c(c) over bars$.