Inclusive semi-leptonic B-meson decay in the QCD-improved parton model

Semi-leptonic B-decay plays an important role in determining the CKM matrix element vertical stroke V_u_b vertical stroke. Whereas the leptonic tensor is completely known, the hadronic tensor of semi-leptonic B-decay is not completely calculable due to non-perturbative QCD effects. In the Light-Cone limit, the hadronic tensor can be expressed with a single distribution function f(x). The interpretation of the distribution function is to parameterize the probability of finding a b-quark with momentum fraction x inside the B-meson, which is similar to the parton model. We apply the parton model to B-meson decay and analyze various subsequent decay spectra. Apart from the naive parton model, we consider further QCD interactions of the b-quark, before it decays into a light-quark and leptons. The distribution function is modified by perturbative QCD corrections. After factorization, the distribution function obtains the dependence of the leptonic invariant mass W"2. We apply Altarelli-Parisi type evolution of the distribution function. QCD corrections to b #-># ulv_l at order #alpha#_s are calculated using the dimensional regularization scheme. The electron energy spectrum, the leptonic invariant mass spectrum, the hadronic energy spectrum, and the hadronic invariant mass spectrum from B-meson decay and b-quark decay are studied and compared. We investigate B-meson decay using the naive parton model and the parton model with an evolved distribution function. (orig.)Available from TIB Hannover: RA 8919(2002-048) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman