An empirical model to determine the hadronic resonance contributions anti B⁰ → anti K^*0 μ⁺μ^- transitions

A method for analysing the hadronic resonance contributions in anti B⁰ → anti K^*0 μ⁺μ^- decays is presented. This method uses an empirical model that relies on measurements of the branching fractions and polarisation amplitudes of final states involving J^PC = 1^-- resonances, relative to the short-distance component, across the full dimuon mass spectrum of anti B⁰ → anti K^*0 μ⁺μ^- transitions. The model is in good agreement with existing calculations of hadronic non-local effects. The effect of this contribution to the angular observables is presented and it is demonstrated how the narrow resonances in the q² spectrum provide a dramatic enhancement to CP-violating effects in the short-distance amplitude. Finally, a study of the hadronic resonance effects on lepton universality ratios, R_K^(*), in the presence of new physics is presented. (orig.)