Tyler Mc Millan Dorland (Deutsches Elektronen-Synchrotron (DE))
Measurements are presented of the properties of top quark pairs in production from proton-proton collisions at the LHC. The data were collected at pp centre-of-mass energies of 7 and 8 !TeV by the CMS experiment during the years 2011 and 2012. The charge asymmetry is measured both inclusively and differentially as function of the invariant mass, the rapidity and the transverse momentum of the ttbar system. The results are compared with various theory predictions, and discussed in the context of forward-backard asymmetry measurements at Tevatron. Top quark spin correlations are also measured using the angular distributions of the top quark decay products. The measurement is performed using top quark events in the lepton+jets channel, with one lepton (electron or muon) and at least four jets, and in the dilepton channel, with two leptons (muon or electron) and at least two jets in the final state. In the dilepton channel the difference in azimuthal angle between the two charged leptons is compared to the expected distributions in the Standard Model.
Dr Kerstin Borras (Deutsches Elektronen-Synchrotron (DE))