Theoretical predictions for $b\to s \mu^+ \mu^-$ decays

TL;DR

This paper reviews the current theoretical calculations for $b o s \, \ell^+ \ell^-$ decays, highlighting tensions with experimental data and discussing the main sources of uncertainties, especially non-local contributions.

Contribution

It provides a comprehensive review of theoretical predictions for $b\to s \mu^+ \mu^-$ decays and introduces a new calculation for the $\\Lambda_b\to \Lambda \mu^+ \mu^-$ channel.

Findings

Theoretical predictions are in tension with experimental measurements.

Non-local contributions are the dominant systematic uncertainties.

Current models cannot fully explain observed discrepancies.

Abstract

I review the state of the art of the theoretical calculations for decays mediated by $b\to s \ell^+ \ell^-$ transitions, for $\ell=e,\mu$. I focus on the predictions of observables in $B\to K \mu^+\mu^-$, $B\to K^* \mu^+\mu^-$, and $B_s\to \phi \mu^+\mu^-$ decays, as many of these predictions are in tension with the corresponding experimental measurements. I also briefly discuss the $\Lambda_b\to \Lambda \mu^+\mu^-$ decay and present a new calculation for this channel. Special emphasis is placed on the non-local contributions, as they are the largest systematic uncertainties in these decays. The current theoretical calculations for $b\to s \mu^+ \mu^-$ decays are not able to explain the tensions with the experimental measurements.