Study of inclusive semileptonic B meson decays

Abstract Using the ARGUS detector at the e + e − storage ring DORIS-II, we have measured the inclusive semileptonic decaysof B-mesonsinto electrons and muons. The data originate from 220.5 events/pb on the ϒ(4S) resonance. We find BR (B→e + v e X = (10.3 ± 0.6 ± 0.2)% and BR (B→ μ + v μ X) = (10.0 ± 0.6 ± 0.2)% using the model of Altarelli et al. for extrapolating over all lepton momenta, and BR (B→e + v e X) = (9.9±0.6)%, BR(B→ μ + v μ X) = (9.7±0.6)% using the model of Grinstein et al. For semileptonic decaysinto baryons, we obtain an upper limit of BR ( B → p e + v X ) CL ) .