Implications of $b\to s$ measurements

TL;DR

This paper analyzes recent measurements of the $b o s o s o s$ transition, revealing a significant deviation from Standard Model predictions, and suggests new physics affecting the Wilson coefficient $C_9$ as a likely explanation.

Contribution

It provides a comprehensive global fit to $b o s o s o s$ data, highlighting a preference for new physics modifying $C_9$ over the Standard Model.

Findings

Significant tension with Standard Model expectations.

Preference for new physics modifying $C_9$ by 3.7σ.

Tension increases to 4.2σ when including $b o se^+e^-$ measurements.

Abstract

The recent updated angular analysis of the $B\to K^*\mu^+\mu^-$ decay by the LHCb collaboration is interpreted by performing a global fit to all relevant measurements probing the flavour-changing neutral current $b\to s\mu^+\mu^-$ transition. A significant tension with Standard Model expectations is found. A solution with new physics modifying the Wilson coefficient $C_9$ is preferred over the Standard Model by $3.7\sigma$. The tension even increases to $4.2\sigma$ including also $b\to se^+e^-$ measurements and assuming new physics to affect the muonic modes only. Other new physics benchmarks are discussed as well. The $q^2$ dependence of the shift in $C_9$ is suggested as a means to identify the origin of the tension - new physics or an unexpectedly large hadronic effect.