Status of the B → K* μ+ μ- anomaly after Moriond 2017

Motivated by recent results by the ATLAS and CMS collaborations on the angular distribution of the B -> K*mu(+)mu-decay, we perform a state-of-the-art analysis of rare B meson decays based on the b -> s mu mu transition. Using standard estimates of hadronic uncertainties, we confirm the presence of a sizeable discrepancy between data and SM predictions. We do not find evidence for a q(2) or helicity dependence of the discrepancy. The data can be consistently described by new physics in the form of a four-fermion contact interaction ((s) over bar gamma(alpha)P(L)b)((mu) over bar gamma(alpha)mu). Assuming that the new physics affects decays with muons but not with electrons, we make predictions for a variety of theoretically clean observables sensitive to violation of lepton flavour universality.