Rare B and strange decays

TL;DR

This paper discusses recent experimental results from LHCb on rare B and strange decays, highlighting deviations from Standard Model predictions and exploring potential new physics or underestimated effects.

Contribution

It presents new LHCb Run 1 and 2 results on rare decay modes, including analyses of charm-resonance contributions and effective lifetime measurements, advancing understanding of potential new physics.

Findings

Deviations observed in $b ightarrow s l^+ l^-$ transitions.

New measurements of $B^0_{(s)} ightarrow \mu^+ \\mu^-$ effective lifetime.

Analysis of charm-resonance effects in $B^+ ightarrow K^+ \\mu^+ \\mu^-$ decays.

Abstract

Several deviations from the Standard Model predictions have been recently observed in the decays mediated by $b \rightarrow s l^+ l^-$ transitions. These could be pointing towards new vector-current contributions or could be explained by underestimated charm-loop effects. New results from an LHCb Run 1 $B^+\rightarrow K^+ \mu^+ \mu^- $ analysis that includes the decays via intermediate charm- resonances are discussed. Also, new results from the fully leptonic rare modes searches are presented. This includes the latest Run 1 and Run 2 $B^0_{(s)} \rightarrow \mu^+ \mu^-$ analysis from LHCb where the $B^0_{s} \rightarrow \mu^+ \mu^-$ candidates are used to determine the effective lifetime of the $B^0_{s} \rightarrow \mu^+ \mu^-$ decays - a pioneering result that in the future will solve the current ambiguity in the (pseudo-)scalar contributions.