Cancellation of power enhancements in non-spectator decays
arXiv:hep-ph/9312234 · doi:10.1016/0370-2693(94)90042-6
Abstract
Exclusive non-spectator decay rates of beauty hadrons contain power enhancements of the form (m_b/m)^2 and m_b/m, where m_b is the b-quark mass and m is a light quark mass. An implicit argument has been recently given according to which these singularities cancel in the totally inclusive decay width. We present in this note a completely explicit computation of the diagrams containing power enhancements. Our results agree with the previous general conclusion.
13 pages, LaTex version 2.09