Current Status of the Standard Model Prediction for the B s → μ + μ − Branching Ratio.

The rare decay B s → μ + μ − provides an important constraint on possible deviations from the Standard Model in b-s-ℓ-ℓ interactions. The present weighted average of its branching ratio measurements amounts to (3.34 ± 0.27) × 10 − 9 , which remains in good agreement with the theoretical prediction of (3.64 ± 0.12) × 10 − 9 within the Standard Model. In the present paper, we review calculations that have contributed to this prediction and discuss the associated uncertainties. [ABSTRACT FROM AUTHOR]