Estimate of B(B̄→Xsγ) at O(αs2)

Abstract

Combining our results for various O(αs2) corrections to the weak radiative B-meson decay, we are able to present the first estimate of the branching ratio at the next-to-next-to-leading order in QCD. We find B(B̄→Xsγ)=(3.15±0.23)×10-4 for Eγ>1.6GeV in the B̄-meson rest frame. The four types of uncertainties: nonperturbative (5%), parametric (3%), higher-order (3%), and mc-interpolation ambiguity (3%) have been added in quadrature to obtain the total error. © 2007 The American Physical Society.