New physics in B → K*μμ?

Recent experimental results on angular observables in the rare decay B -> K*mu(+)mu(-) show significant deviations from Standard Model predictions. We investigate the possibility that these deviations are due to new physics. Combining all relevant data on b -> s rare decays, we show that a consistent explanation of most anomalies can be obtained by new physics contributing simultaneously to the semi-leptonic vector operator O-9 and its chirality-flipped counterpart O-9'. A partial explanation is possible with new physics in O-9 or in dipole operators only. We study in detail the implications for models of new physics, in particular the minimal supersymmetric standard model, models with partial compositeness and generic models with flavour-changing Z' bosons. In all considered models, contributions to B -> K*mu(+)mu(-) of the preferred size imply a spectrum close to the TeV scale. We stress that measurements of CP asymmetries in B -> K*mu(+)mu(-) could provide valuable information to narrow down possible new physics explanations.