Cancellation of 1/m(Q) corrections to the inclusive decay width of a heavyquark - art. no. 114025

We consider the infrared sensitivity of the inclusive heavy quark decay wid th in perturbation theory. It is shown by explicit calculations to the seco nd loop order (when the non-Abelian nature of the QCD interactions first be come apparent) that all infrared sensitive terms to logarithmic and linear accuracy cancel when the decay width is expressed in terms of the short dis tance mass. This in turn implies the absense of any nonperturbative 1/m(Q) power corrections to the decay width. The cancellation is shown algebraical ly at the level of the Feynman integrands without any use of an explicit in frared cutoff. This result is in accordance with the implications of the KL N theorem. [S0556-2821(98)08619-6].