Measurement of the top pair production cross section in 8 TeV proton-proton collisions using kinematic information in the lepton+ jets final state with ATLAS

A measurement is presented of the tt¯ inclusive production cross section in pp collisions at a center-of-mass energy of s=8TeV 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 20.3fb-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 tt¯ production cross section was measured to be 260$\pm$1(stat)-23+22(stat)$\pm$8(lumi)$\pm$4(beam)pb assuming a top-quark mass of 172.5 GeV, in good agreement with the theoretical prediction of 253-15+13pb. The tt¯→(e,μ)+jets production cross section in the fiducial region determined by the detector acceptance is also reported. \copyright 2015 CERN, for the ATLAS Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.