Aaboud, M.Aad, G.Abbott, B.Abbott, D. C.Abdinov, O.Abed Abud, A.Abhayasinghe, D. K.Izen, Joseph M.Meirose, BernhardReeves, KendallATLAS CollaborationCMS Collaboration2020-03-032020-03-032019-05-161126-6708http://dx.doi.org/10.1007/JHEP05(2019)088https://hdl.handle.net/10735.1/7328This 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 √s = 7 and 8 TeV corresponding to integrated luminosities of 1.17 to 5.1 fb⁻¹ at √s = 7 TeV and 12.2 to 20.3 fb⁻¹ at √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 √s = 7 and 8 TeV respectively. The combined tW cross-sections are 16.3 ± 4.1 pb and 23.1 ± 3.6 pb at √s = 7 and 8 TeV respectively. For the s-channel cross-section, the combination yields 4.9 ± 1.4 pb at √s = 8 TeV. The square of the magnitude of the CKM matrix element V_{tb} multiplied by a form factor fLV 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 |fLVV_{tb}|² determinations, extracted from individual ratios at √s = 7 and 8 TeV, are combined, resulting in |fLVV_{tb}| = 1.02 ± 0.04 (meas.) ± 0.02 (theo.). All combined measurements are consistent with their corresponding Standard Model predictions. © 2019, The Author(s).enCC BY 4.0 (Attribution)©2019 CERN for the benefit of the ATLAS-CMS Collaborationhttp://creativecommons.org/licenses/by/4.0/Hadron-hadron scattering (experiments)Particles (Nuclear physics)--FlavorLarge Hadron Collider (France and Switzerland)Proton-proton interactionsStandard model (Nuclear physics)articleAaboud, M., G. Aad, B. Abbott, D. C. Abbott, et al. 2019. "Combinations of single-top-quark production cross-section measurements and |fLVV_{tb}| determinations at √s = 7 and 8 TeV with the ATLAS and CMS experiments." Journal of High Energy Physics 2019(5): art. 88, doi: 10.1007/JHEP05(2019)08820195