Combination of ATLAS and CMS results on the mass of the top quark using up to 4.9 fb−1 of data

A combination of top-quark mass measurements performed by the ATLAS and CMS experiments at the LHC is presented. The dataset used corresponds to an integrated luminosity per experiment of up to 4.9 inverse fb of proton-proton collisions at a centre-of-mass energy of 7 TeV. The combination includes measurements in the ttbar lepton+jets, di-lepton and all jets channels. The resulting preliminary combined LHC measurement of the top-quark mass is mtop = 173.3 ± 0.5 (stat) ± 1.3 (syst) GeV, with a total uncertainty of 1.4 GeV.