Updated Next-to-Next-to-Leading-Order QCD Predictions for the Weak Radiative B -Meson Decays

M. Misiak, H. M. Asatrian, R. Boughezal, M. Czakon, T. Ewerth, A. Ferroglia, P. Fiedler, P. Gambino, C. Greub, U. Haisch, T. Huber, M. Kamiński (+6 others)
2015 Physical Review Letters  
Weak radiative decays of the B mesons belong to the most important flavor changing processes that provide constraints on physics at the TeV scale. In the derivation of such constraints, accurate standard model predictions for the inclusive branching ratios play a crucial role. In the current Letter we present an update of these predictions, incorporating all our results for the O(alpha_s^2) and lower-order perturbative corrections that have been calculated after 2006. New estimates of
more » ... ative effects are taken into account, too. For the CP- and isospin-averaged branching ratios, we find B_s gamma = (3.36 +_ 0.23) * 10^-4 and B_d gamma = 1.73^+0.12_-0.22 * 10^-5, for E_gamma > 1.6GeV. Both results remain in agreement with the current experimental averages. Normalizing their sum to the inclusive semileptonic branching ratio, we obtain R_gamma = ( B_s gamma + B_d gamma)/B_c l nu = (3.31 +_ 0.22) * 10^-3. A new bound from B_s gamma on the charged Higgs boson mass in the two-Higgs-doublet-model II reads M_H^+ > 480 GeV at 95
doi:10.1103/physrevlett.114.221801 pmid:26196614 fatcat:3cvpjul32vhpdcbcocranqho3u