Combination of inclusive and differential $t\overline{t}$ charge asymmetry measurements using ATLAS and CMS data at $\sqrt{s}=7$ and 8 TeV

This paper presents combinations of inclusive and differential measurements of the charge asymmetry ($A_C$) in top quark pair ($t\overline{t}$) events with a lepton+jets signature by the ATLAS and CMS Collaborations, using data from LHC proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. The data correspond to integrated luminosities of about 5 and $20$ fb${}^{-1}$ for each experiment, respectively. The resulting combined LHC measurements of the inclusive charge asymmetry are $A_C^{LHC7}=0.005\pm 0.007\left(stat\right)\pm 0.006\left(syst\right)$ at 7 TeV and $A_C^{LHC8}=0.0055\pm 0.0023\left(stat\right)\pm 0.0025\left(syst\right)$ at 8 TeV. These values, as well as the combination of $A_C$ measurements as a function of the invariant mass of the $t\overline{t}$ system at 8 TeV, are consistent with the respective standard model predictions.