Addendum to ‘Measurement of the [equation] production cross-section using [equation] events withb-tagged jets inppcollisions at [equation] = 7 and 8? [equation] with the ATLAS detector’

摘要

The ATLAS measurement of the inclusive top quark pair ((tar{t})) cross-section (sigma _{tar{t}}) in proton–proton collisions at (sqrt{s}=8)?(,mathrm{TeV}) has been updated using the final 2012 luminosity calibration. The updated cross-section result is: $$egin{aligned} sigma _{tar{t}}= 242.9pm 1.7pm 5.5pm 5.1pm 4.2,mathrm pb, end{aligned}$$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 (tar{t}) cross-sections at (sqrt{s}=8)?(,mathrm{TeV}) and (sqrt{s}=7)?(,mathrm{TeV}), and the (sqrt{s}=8)?(,mathrm{TeV}) fiducial measurement corresponding to the experimental acceptance of the leptons, have also been updated.