The Rule of Discarding $1/N_c$ in Inclusive Weak Decays. II

Abstract

We calculate the leading preasymptotic correction to the inclusive width $b\to \bar{c}cs$ (two massive quarks in the final state) due to the operator $\vec{\sigma }\vec{H}$. It is found that this correction tends to cancel the $1/N_c$ part of the inclusive width calculated using naive factorization. The absolute value of the effect is of order 0.25. We also discuss how quark-hadron duality is realized in the inclusive decays.

Comments: preprint NSF-ITP-92-115,TPI-MINN-92/52-T 20 pages, latex file