Speaker
Description
For several years, many long-standing anomalies in rare $b \to s\ell \bar\ell$ decays have raised questions about possible hints of physics beyond the Standard Model (SM). These anomalies appear not only in branching ratios of $B\to K$, $B\to K^*$, and $B_s\to \phi$ in both high- and low-$q^2$ regions (with $q^2$ the invariant mass of the dilepton pair), but also in angular observables such as $P_5'$, and are consistent with a $\sim 20-25\%$ shift to the SM Wilson coefficient $C_9$, potentially from new physics. However, with the recent disappearance of anomalies in the lepton flavor universality violating ratios $R_K$ and $R_{K^*}$, doubts have been raised about such new-physics interpretations, particularly due to long-distance charm rescattering effects which are as-yet incalculable within the SM. In this talk, I will give an overview of the current status of anomalies in $b\to s\ell \bar\ell$ decays as well as discuss the first steps taken towards estimating the possible size of such charm rescattering effects.
