Exclusive measurements of b→sγ transition rate and photon energy spectrum

Abstract

We use 429fb -1 of e +e - collision data collected at the Υ(4S) resonance with the BABAR detector to measure the radiative transition rate of b→sγ with a sum of 38 exclusive final states. The inclusive branching fraction with a minimum photon energy of 1.9 GeV is found to be B(B̄→X sγ)=(3.29±0.19±0. 48)×10 -4 where the first uncertainty is statistical and the second is systematic. We also measure the first and second moments of the photon energy spectrum and extract the best-fit values for the heavy-quark parameters, m b and μπ2, in the kinetic and shape function models. © 2012 American Physical Society.