On the standard model predictions for RK R K and RK^* R K ∗

We evaluate the impact of radiative corrections in the ratios Γ [B→ M μ ⁺μ ⁻]/Γ [B→ M e⁺e⁻] when the meson M is a K or a K^* . Employing the cuts on m² 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.