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This paper presents the combinations of single-top-quark production cross-section measurements by the ATLAS and CMS Collaborations, using data from LHC proton-proton collisions at $$ \sqrt{s} $$ = 7 and 8 TeV corresponding to integrated luminosities of 1.17 to 5.1 fb$$^{−1}$$ at $$ \sqrt{s} $$ = 7 TeV and 12.2 to 20.3 fb$$^{−1}$$ at $$ \sqrt{s} $$ = 8 TeV. These combinations are performed per centre-of-mass energy and for each production mode: t-channel, tW, and s-channel. The combined t-channel cross-sections are 67.5 ± 5.7 pb and 87.7 ± 5.8 pb at $$ \sqrt{s} $$ = 7 and 8 TeV respectively. Themore » combined tW cross-sections are 16.3 ± 4.1 pb and 23.1 ± 3.6 pb at $$ \sqrt{s} $$ = 7 and 8 TeV respectively. For the s-channel cross-section, the combination yields 4.9 ± 1.4 pb at $$ \sqrt{s} $$ = 8 TeV. The square of the magnitude of the CKM matrix element V$$_{tb}$$ multiplied by a form factor f$$_{LV}$$ is determined for each production mode and centre-of-mass energy, using the ratio of the measured cross-section to its theoretical prediction. It is assumed that the top-quark-related CKM matrix elements obey the relation |V$$_{td}$$|, |V$$_{ts}$$| ≪ |V$$_{tb}$$|. All the |f$$_{LV}$$V$$_{tb}$$|$$^{2}$$ determinations, extracted from individual ratios at $$ \sqrt{s} $$ = 7 and 8 TeV, are combined, resulting in |f$$_{LV}$$V$$_{tb}$$| = 1.02 ± 0.04 (meas.) ± 0.02 (theo.). All combined measurements are consistent with their corresponding Standard Model predictions.« less

This paper presents combinations of inclusive and differential measurements of the charge asymmetry (A$$_{C}$$) in top quark pair $$ \left(\mathrm{t}\overline{\mathrm{t}}\right) $$ 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$$_{C}^{CHC7}$$  = 0.005 ± 0.007 (stat) ± 0.006(syst) at 7 TeV and A$$_{C}^{CHC8}$$  = 0.0055 ± 0.0023 (stat) ± 0.0025 (syst) at 8 TeV. These values, as well as the combination of A$$_{C}$$ measurements as a function of the invariantmore » mass of the $$ \mathrm{t}\overline{\mathrm{t}} $$ system at 8 TeV, are consistent with the respective standard model predictions.« less