Measurement of angular parameters from the decay B⁰ → K^⁎0μ⁺μ⁻ in proton–proton collisions at s=8TeV

Angular distributions of the decay B⁰→K^⁎0μ⁺μ⁻ are studied using a sample of proton–proton collisions at s=8TeV collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 20.5fb⁻¹. An angular analysis is performed to determine the P₁ and P₅ ^′ parameters, where the P₅ ^′ parameter is of particular interest because of recent measurements that indicate a potential discrepancy with the standard model predictions. Based on a sample of 1397 signal events, the P₁ and P₅ ^′ parameters are determined as a function of the dimuon invariant mass squared. The measurements are in agreement with predictions based on the standard model.