Analysis of B(B-->Xsgamma) at next-to-next-to-leading order with a cut on photon energy.
By combining a recent estimate of the total B-->X(s)gamma branching fraction at O(alpha(s)2) with a detailed analysis of the effects of a cut E(gamma)>or=1.6 GeV on photon energy, a prediction for the partial B-->Xsgamma branching fraction at next-to-next-to-leading order in renormalization-group improved perturbation theory is obtained, in which contributions from all relevant scales are factorized. The result B(B-->Xsgamma)=(2.98+/-0.26) x 10(-4) is about 1.4 sigma lower than the experimental world average. This opens a window for significant new physics contributions in rare radiative B decays.
Becher
Thomas
T
Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, Illinois 60510, USA.
Neubert
Matthias
M