The measurement of the charge asymmetry in the ttbar dilepton channel has been performed at the LHC proton-proton collision energy of 7 TeV. This measurement has been realized for a total integrated luminosity of 5.0/fb , corresponding to the dilepton data set collected during the year 2011 by the CMS experiment. The inclusive asymmetry has been measured to be 0.050+-0.043(stat)+0.010-0.039(syst). The measurement is also given in a differential form, as a function of the invariant mass, the transverse momenta and the rapidity of the ttbar system. In addition, the inclusive charge asymmetry based on the lepton rapidities is measured to be 0.010+-0.015+-0.006. All measurements are consistent with their stardard model expectations.
Figure / Table | Abbreviated Caption |
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Estimate of the W+jet like and QCD like background for the three channels. |
Selection efficiency (fraction of number selected events to number of generated events) as estimated in our analysis and used in the unfolding procedure for the sensitive variable. |
Migration matrix as estimated in our analysis and used in the unfolding procedure for the sensitive variable. |
Migration matrix as estimated in our analysis and used in the unfolding procedure for the sensitive variable over the invariant mass of the top pair system. |
Unfolded results compared to theoretical predictions. Inclusive measurement. |
Unfolded results compared to theoretical predictions. Differential asymmetry in the invariant mass of the top pair system. |
Unfolded results compared to theoretical predictions. Differential asymmetry in the rapidity of the top pair system. |
Unfolded results compared to theoretical predictions. Differential asymmetry in the transverse momenta of the top pair system. |
Dependence of the unfolded top forward-backward asymmetry on the invariant mass of the top pair system. |