B_s --> \gamma \gamma decay in the two Higgs doublet model with flavor changing neutral currents

Abstract

We calculate the leading logarithmic QCD corrections to the decay B_{s} -->\gamma\gamma in the two Higgs doublet model with tree level flavor changing currents (model III) including O_7 type long distance effects. Further, we analyse the dependencies of the branching ratio Br(B_{s} --> \gamma\gamma)$andtheratioofCP-evenandCP-oddamplitudesquares,R=|A^{+}{|}^2/|A^{-}{|}^2,onthechargedHiggsmass{m}_{H^{\pm }}andtheselectedmodelIIIparameters{\xi }^{U,D}includingtheleadinglogarithmicQCDcorrections.ItisfoundthattolookforchargedHiggseffects,themeasurementofthebranchingratioBr(B_s-->\gamma \gamma )$ is promising.

Comments: 21 pages, 17 figures