Lifetime-difference pattern of heavy hadrons

The preasymptotic effects originating from the four-quark operators are dis entangled from the other contributions by considering appropriate combinati ons of inclusive decay rates. Under the assumption of the isospin and heavy -quark symmetry, a set of relations connecting charmed and beauty decays is obtained without invoking specific models. The results are compared with o ther approaches and confronted with experiment. (C) 2000 Elsevier Science B .V. All rights reserved.