Measurement of the t-tbar differential cross-section in pp collisions at radq(s) = 7 TeV

Three measurements of t-tbar differential cross section at √s = 7 TeV in pp collisions at the Large Hadron Collider (LHC) are presented: with respect to transverse momentum, mass and rapidity of the ttbar system. Top pair production cross section measurements can be used to test perturbative QCD. In particular, with the high statistics collected in LHC it is possible to measure the differential cross section and look for possible deviations from the Standard Model. The results presented here have been obtained using part of the data collected by the ATLAS detector during the 2011 corresponding to an integrated luminosity of ∼ 2fb^(−1). The extension of the analysis to the full 2011 data sample (∼ 5fb(−1)) is ongoing. The events are selected with a cut-based approach in the single lepton plus jets decay channel, where the lepton can be either an electron or a muon. The final background-subtracted distributions are corrected for the distortion introduced by the detector and selection effects using unfolding methods. The measurements are dominated by the systematic uncertainties and show a good agreement with the Standard Model predictions.