A measurement is presented of the t t inclusive production cross section in p p collisions at a center-of-mass energy of s= 8 TeV using data collected by the ATLAS detector at the CERN Large Hadron Collider. The measurement was performed in the lepton+ jets final state using a data set corresponding to an integrated luminosity of 20.3 fb− 1. The cross section was obtained using a likelihood discriminant fit and b-jet identification was used to improve the signal-to-background ratio. The inclusive t t production cross section was measured to be 260±1 (stat)− 23+ 22 (stat)±8 (lumi)±4 (beam) pb assuming a top-quark mass of 172.5 GeV, in good agreement with the theoretical prediction of 253− 15+ 13 pb. The t t→(e, μ)+ jets production cross section in the fiducial region determined by the detector acceptance is also reported.
