Short- vs Long-Distance Dynamics in $b\to s\bar{\mathrm{\ell }}\mathrm{\ell }$ Decays

The tension of $B\to K^{(\ast )}\bar{\mathrm{\ell }}\mathrm{\ell }$ decays with the Standard Model (SM) can be attributed to a short-distance (SD) $bs\bar{\mathrm{\ell }}\mathrm{\ell }$ interaction. We show two methods to disentangle this effect from long-distance (LD) dynamics. Firstly, we perform a comparison of the inclusive $b\to s\bar{\mathrm{\ell }}\mathrm{\ell }$ rate at high $q^2=m_{\mathrm{\ell }\mathrm{\ell }}^2\ge 15\mathrm{G}\mathrm{e}{\mathrm{V}}^2$ with a determination based on data on the leading exclusive modes, finding a $\sim 2\sigma$ discrepancy. Secondly, we analyze the exclusive $B\to K^{(\ast )}\bar{\mathrm{\ell }}\mathrm{\ell }$ spectrum in the entire $q^2$ region. With a dispersive parametrization of the charmonia resonances, we extract the non-SM contribution to the Wilson coefficient $C_9$ for every bin in $q^2$. The result is compatible with the SD hypothesis and the inclusive determination. Finally, with the aim of having better control over LD effects that mimic the $C_9$ contribution, we estimate the size of a few charm-rescattering processes in $B\to K\bar{\mathrm{\ell }}\mathrm{\ell }$.