Estimate of BR(B -> X_s gamma) at O(alpha_s^2)
/ Authors
M. Misiak, H. Asatrian, K. Bieri, M. Czakon, A. Czarnecki, T. Ewerth, A. Ferroglia, P. Gambino, M. Gorbahn, C. Greub
and 7 more authors
U. Haisch, A. Hovhannisyan, T. Hurth, A. Mitov, Poghosyan, M. Ślusarczyk, M. Steinhauser
/ Abstract
Combining our results for various O(alpha_s^2) 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 BR(B -> X_s gamma) = (3.15 +_ 0.23) x 10^-4 for E_gamma > 1.6 GeV in the B-meson rest frame. The four types of uncertainties: non-perturbative (5%), parametric (3%), higher-order (3%) and m_c-interpolation ambiguity (3%) have been added in quadrature to obtain the total error.
Journal: Physical Review Letters