B_s ---> \gamma \gamma decay in the model III and 3HDM(O_2) with CP violating effects

Abstract

We analyse the CP asymmetry for B_{s} -->\gamma\gamma in the two Higgs doublet model with tree level flavor changing currents (model III) and three Higgs doublet model with O_2 symmetry in the Higgs sector, including O_{7} type long distance effects. Further, we study the dependencies of the branching ratio Br(B_{s} --> \gamma\gamma)$ and the ratio of CP-even and CP-odd amplitude squares, R=|A^{+}|^2/|A^{-}|^2, on the CP parameter sin \theta. We found that, there is a weak CP asymmetry, at the order of 10^{-4}. Besides, the branching ratio Br(B_{s} --> \gamma\gamma), and also R ratio, is not sensitive to the CP parameter for |\frac{\bar{\xi}^{U}_{N,tt}}{\bar{\xi}^{D}_{N,bb}}|<1.