ISSN - 03702693, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2002, vol. 547, p. 181-192
Measurement of the inclusive semileptonic branching fraction of B mesons and |Vcb|
We present a measurement of the electron spectrum from inclusive semileptonic B decay, using 5.1 fb-1 of γ(4S) data collected with the Belle detector. A high-momentum lepton tag was used to separate the semileptonic B decay electrons from secondary decay electrons. We obtained the branching fraction, β(B → Xe+v) = (10.90 ± 0.12 ± 0.49)%, with minimal model dependence. From this measurement, we derive a value for the Cabibbo-Kobayashi-Maskawa matrix element |Vcb|= 0.0408 ± 0.0010(exp) ± 0.0025(th). © 2002 Elsevier Science B.V. All rights reserved.