We present our results for three-loop anomalous dimensions necessary in analyzing $B{ \to}X_s\gamma$ decay at the next-to-leading order in QCD. We combine them with other recently calculated contributions, obtaining a practically complete next-to-leading order prediction for the branching ratio ${ \cal B}(B{ \to}X_s\gamma) = (3.28 \pm 0.33) \times 10^{ -4}$. The uncertainty is more than twice smaller than in the previously available leading order theoretical result. The Standard Model prediction remains in agreement with the CLEO measurement at the $2 \sigma$ level.
Categories: hep-ph