Addendum to 'Measurement of the tt¯ production cross-section using eμ events with b -tagged jets in pp collisions at s = 7 and 8 TeV with the ATLAS detector'

The ATLAS measurement of the inclusive top quark pair ( tt¯ ) cross-section σtt¯ in proton–proton collisions at s=8  TeV has been updated using the final 2012 luminosity calibration. The updated cross-section result is: σtt¯=242.9±1.7±5.5±5.1±4.2pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, knowledge of the integrated luminosity and of the LHC beam energy. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. The measurement of the ratio of tt¯ cross-sections at s=8  TeV and s=7  TeV , and the s=8  TeV fiducial measurement corresponding to the experimental acceptance of the leptons, have also been updated.