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

TL;DR

This paper investigates CP asymmetry and branching ratios in B_s to gamma gamma decays within two Higgs doublet models, revealing weak CP asymmetry and limited sensitivity to CP parameters.

Contribution

It provides a detailed analysis of CP asymmetry and decay rates in specific two Higgs doublet models, including effects of long-distance contributions and CP violation.

Findings

CP asymmetry is approximately 10^{-4}

Branching ratio is insensitive to CP parameter for certain Yukawa ratios

R ratio shows limited dependence on CP parameter

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.