ISSN - 03702693, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2005, vol. 614, p. 27-36
Spectra of prompt electrons from decays of B + and B 0 mesons and ratio of inclusive semielectronic branching fractions
We present spectra of prompt electrons from decays of neutral and charged B mesons. The results are based on 140 fb -1 of data collected by the Belle detector on the Υ(4S) resonance at the KEKB e +e - asymmetric collider. We tag Υ(4S)→BB̄ events by reconstructing a B meson in one of several hadronic decay modes; the semileptonic decay of the other B meson is inferred from the presence of an identified electron. We obtain for charged and neutral B mesons the partial rates of semileptonic decay, to electrons with momentum greater than 0.6 GeV/c in the B rest frame, and their ratio b +/b 0=1.08±0. 05±0.02, where the first and second errors are statistical and systematic, respectively. © 2005 Elsevier B.V. All rights reserved.