Aad, G.Abbott, B.Abeling, K.Abicht, N. J.Abidi, S. H.Aboulhorma, A.Çetin, Serkant Ali2024-05-192024-05-1920240370-26931873-2445https://doi.org10.1016/j.physletb.2023.138376https://hdl.handle.net/20.500.12713/5735The inclusive top-quark-pair production cross section rrtt and its ratio to the Z-boson production cross section have been measured in proton-proton collisions at root s = 13.6 TeV, using 29 fb-1 of data collected in 2022 with the ATLAS experiment at the Large Hadron Collider. Using events with an opposite-charge electron-muon pair and b-tagged jets, and assuming Standard Model decays, the top-quark-pair production cross section is measured to be rrtt = 850 +/- 3(stat.) +/- 18(syst.) +/- 20(lumi.) pb. The ratio of the ttand the Z-boson production cross sections is also measured, where the Z-boson contribution is determined for inclusive e+e- and mu+mu- events in a fiducial phase space. The relative uncertainty on the ratio is reduced compared to the ttcross section, thanks to the cancellation of several systematic uncertainties. The result for the ratio, Rtt/Z = 1.145 +/- 0.003(stat.) +/- 0.021(syst.) +/- 0.002(lumi.) is consistent with the Standard Model prediction using the PDF4LHC21 PDF set.eninfo:eu-repo/semantics/openAccessPlus PlusArticle848WOS:0011364413000012-s2.0-85183680739N/A10.1016/j.physletb.2023.138376Q1