Measurements of spin correlation in top-antitop quark events from proton-proton collisions at √s = 7 TeV using the ATLAS detector

Measurements of spin correlation in top quark pair production are presented using data collected with the ATLAS detector at the LHC with proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 4.6 fb−1. Events are selected in final states with two charged leptons and at least two jets. Four different observables sensitive to different properties of the production mechanism are used to extract the correlation between the top and antitop quark spins. Some of these observables are measured for the first time. All measurements are in good agreement with the next-to-leading-order Standard Model prediction.