Current Status of the Standard Model Prediction for the B_s -> mu^+ mu^- Branching Ratio

TL;DR

This paper reviews the current theoretical predictions and experimental measurements of the B_s -> mu^+ mu^- decay, highlighting their agreement and discussing uncertainties in the Standard Model context.

Contribution

It provides a comprehensive review of calculations and uncertainties related to the Standard Model prediction for the B_s -> mu^+ mu^- decay branching ratio.

Findings

Experimental measurement: (3.34 ± 0.27) x 10^-9

Theoretical prediction: (3.64 ± 0.12) x 10^-9

Good agreement between measurement and theory

Abstract

The rare decay B_s -> mu^+ mu^- 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 \pm 0.27) x 10^-9, which remains in good agreement with the theoretical prediction of (3.64 \pm 0.12) x 10^-9 within the Standard Model. In the present paper, we review calculations that have contributed to this prediction, and discuss the associated uncertainties.