Measurement of the ratio B(B+→Xeν)/B(B0→Xeν)

We report measurements of the inclusive electron momentum spectra in decays of charged and neutral B mesons, and of the ratio of semileptonic branching fractions B(B+→Xeν) and B(B0→Xeν). These were performed on a sample of 231×106 BB events recorded with the BABAR detector at the Υ(4S) resonance. Events are selected by fully reconstructing a hadronic decay of one B meson and identifying an electron among the decay products of the recoiling B meson. We obtain B(B+→Xeν)/B(B0→Xeν)=1. 074±0.041(stat)±0.026(syst). © 2006 The American Physical Society.