ISSN - 00319007, EISSN - 10797114, Physical Review Letters, 2005, vol. 95, p. -
Measurement of the branching fraction of Υ(4S)→B0B̄0
We report the first measurement of the branching fraction f00 for Υ(4S)→B0B̄0. The data sample consists of 81.7fb-1 collected at the Υ(4S) resonance with the BABAR detector at the SLAC PEP-II asymmetric-energy e+e- storage ring. Using partial reconstruction of the decay B̄0→D*+ -ν̄ in which only the charged lepton and the soft pion from the decay D*+→D0π+ are reconstructed, we obtain f00=0.487±0.010(stat)±0.008(syst). Our result does not depend on the branching fractions of B̄0→D*+ -ν̄ and D*+→D0π+ decays, on the ratio of the charged and neutral B meson lifetimes, nor on the assumption of isospin symmetry. © 2005 The American Physical Society.