OPERATOR PRODUCT EXPANSION FOR INCLUSIVE SEMILEPTONIC DECAYS IN HEAVY-QUARK EFFECTIVE-FIELD THEORY

Inclusive semileptonic decays are discussed in the framework of heavy quark effective field theory by employing the short-distance expansion in the effective theory. The lowest order term turns out to be the pa rton model; the higher order terms may be regarded as correction terms to the parton model result. The first nonvanishing corrections to the parton model result are given and the lepton energy spectrum of inclu sive semileptonic decays of heavy mesons is calculated.