Studies for the charge asymmetry measurement in top quark pair production in pp collisions at Vs= 8 TeV using the ATLAS detector

The charge asymmetry AC, predicted by QCD at NLO in the top-antitop quarks pair production, is an important test of the SM predictions at high energies, but is also very sensitive to new Physics. The asymmetry could be altered by the presence of new particles coupling to top quarks, whose effects cannot be seen in the tt invariant mass spectrum.