On the Long Distance Contribution to the $B_s\to \gamma\gamma$ Decay in the Effective Lagrangian Approach

TL;DR

This paper reevaluates the $B_s o ext{gamma gamma}$ decay rate using an effective Lagrangian approach, finding a lower branching ratio than previously claimed, which impacts theoretical predictions of this rare decay.

Contribution

The study provides a revised estimate of the $B_s o ext{gamma gamma}$ decay branching ratio, challenging recent higher estimates and refining theoretical understanding.

Findings

Branching ratio does not exceed a few times 10^{-7}

Contradicts recent literature claiming higher rates

Uses effective Lagrangian approach for re-estimation

Abstract

We re-estimate the decay branching ratio of $B_s\to 2\gamma$ through $D_s^+D_s^-$ and $D_s^{*+}D_s^{*-}$ intermediate states, in the effective Lagrangian approach. We find that the branching ratio does not exceed a few times $10^{-7}$, contrary to the result recently claimed in the literature.