A measurement of the top-antitop (tt¯) charge asymmetry is presented using data corresponding to an integrated luminosity of 4.6 fb−1 of LHC pp collisions at a centreof-mass energy of 7 TeV collected by the ATLAS detector. Events with two charged leptons, at least two jets and large missing transverse momentum are selected. Two observables are studied: AC ℓℓ based on the identified charged leptons, and (Formula Presented.), based on the reconstructed tt final state. The asymmetries are measured to be (Formula Presented.). The measured values are in agreement with the Standard Model predictions.[Figure not available: see fulltext.] © 2015, The Author(s).

Measurement of the charge asymmetry in dileptonic decays of top quark pairs in pp collisions at √s = 7 TeV using the ATLAS detector

BRAZZALE, Simone Federico;COBAL, Marina;GIORDANI, Mario;Monzani, S.;