Second order QCD corrections to the nonleptonic decay of the b quark in the slow charm limit

The perturbative QCD corrections to the nonleptonic decay rate of the 6 quark are discussed. By considering the limit where the final charmed quarks are slow, it is argued that the coefficients of the α_s² terms, corresponding to the next-to-next-to-leading order in the standard renormalization group expansion in ln(m_w/m_b), are naturally large. The large coefficients arise from the final state gluon exchange between quarks and are associated with the region of rather low momenta, which may further enhance the phenomenological significance of these terms.