Angular analysis of charged and neutral B → Kμ + μ − decays

Abstract

The angular distributions of the rare decays B + → K + μ + μ − and B0→K0Sμ+μ− are studied with data corresponding to 3fb−1 of integrated luminosity, collected in proton-proton collisions at 7 and 8 TeV centre-of-mass energies with the LHCb detector. The angular distribution is described by two parameters, F H and the forward-backward asymmetry of the dimuon system A FB, which are determined in bins of the dimuon mass squared. The parameter F H is a measure of the contribution from (pseudo)scalar and tensor amplitudes to the decay width. The measurements of A FB and F H reported here are the most precise to date and are compatible with predictions from the Standard Model.