Speaker
Maria Ilaria Besana
(Torino)
Description
The measurement of the charge asymmetry in top quark pair production can be an important window on new physics, as in some Beyond Standard Model theories this asymmetry is significantly enhanced with respect to Standard Model prediction. The measurements performed by the ATLAS collaboration with pp collision data recorded in 2011 will be presented. The analysis has been performed in the semileptonic channel. Signal candidate events have been selected requiring the presence of a single lepton (electron or muon), large missing transverse energy and at least four jets, one of them tagged as a b-jet. A kinematic likelihood has then been used to reconstruct the top quark pair event topology. After background subtraction, a Bayesian unfolding procedure has been applied to correct for acceptance and detector effects. The main background processes and the data-driven techniques to estimate their contribution will be presented. The unfolding technique will be then illustrated and systematics uncertainties will be discussed. A comparison between measured and predicted asymmetry will be finally shown.
Primary author
Maria Ilaria Besana
(Torino)
