Differential branching fraction and angular analysis of the decay B 0 → K ∗0 μ + μ −

A bstract The angular distribution and differential branching fraction of the decay B 0 → K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at $ \sqrt{s}=7 $ TeV, corresponding to an integrated luminosity of 1 . 0 fb −1 . Several angular observables are measured in bins of the dimuon invariant mass squared, q 2 . A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be $ q_0^2={{{4.9\pm 0.9\;\mathrm{Ge}{{\mathrm{V}}^2}}} \left/ {{{c^4}}} \right.} $ , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions.