Combination of measurements of the top quark mass from data collected by the ATLAS and CMS experiments at √s = 7 and 8 TeV

A combination of fifteen top quark mass measurements performed by the ATLAS and CMS experiments at the LHC is presented. The data sets used correspond to an integrated luminosity of up to 5 and 20 fb−1 of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, respectively. The combination includes measurements in top-quark pair events that exploit both the semileptonic and hadronic decays of the top quark, and a measurement using events enriched in single top quark production via the electroweak t-channel. The combination yields mt = 172.52 ± 0.14 (stat) ± 0.30 (syst) GeV, with a total uncertainty of 0.33 GeV.