On the standard model predictions for RK and RK∗

Abstract

We evaluate the impact of radiative corrections in the ratios Γ [B→ Mμ+μ-]/Γ [B→ Me +e-] when the meson M is a K or a K∗. Employing the cuts on mℓℓ2 and the reconstructed B-meson mass presently applied by the LHCb Collaboration, such corrections do not exceed a few %. Moreover, their effect is well described (and corrected for) by existing Monte Carlo codes. Our analysis reinforces the interest of these observables as clean probe of physics beyond the Standard Model.