TY - JOUR AU - ATLAS Collaboration (Aad, G. et al AU - Aparisi Pozo, J. A. AU - Bailey, A. J. AU - Cabrera Urban, S. AU - Cardillo, F. AU - Castillo, F. L. AU - Castillo Gimenez, V. AU - Costa, M. J. AU - Didenko, M. AU - Escobar, C. AU - Estrada Pastor, O. AU - Ferrer, A. AU - Fiorini, L. AU - Fullana Torregrosa, E. AU - Fuster, J. AU - Garcia, C. AU - Garcia Navarro, J. E. AU - Gonzalez de la Hoz, S. AU - Gonzalvo Rodriguez, G. R. AU - Guerrero Rojas, J. G. R. AU - Higon-Rodriguez, E. AU - Lacasta, C. AU - Lozano Bahilo, J. J. AU - Mamuzic, J. AU - Marti-Garcia, S. AU - Martinez Agullo, P. AU - Miralles Lopez, M. AU - Mitsou, V. A. AU - Moreno Llacer, M. AU - Navarro-Gonzalez, J. AU - Poveda, J. AU - Prades IbaƱez, A. AU - Ruiz-Martinez, A. AU - Sabatini, P. AU - Salt, J. AU - Sanchez Sebastian, V. AU - Sayago Galvan, I. AU - Soldevila, U. AU - Sanchez, J. AU - Torro Pastor, E. AU - Valero, A. AU - Valls Ferrer, J. A. AU - Villaplana Perez, M. AU - Vos, M. PY - 2021 DA - 2021// TI - Measurement of the t(t)over-bart(t)over-bar production cross section in pp collisions at root s=13 TeV with the ATLAS detector T2 - J. High Energy Phys. JO - Journal of High Energy Physics SP - 118 EP - 53pp VL - 11 IS - 11 PB - Springer KW - Hadron-Hadron scattering (experiments) KW - Top physics AB - A measurement of four-top-quark production using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the Large Hadron Collider corresponding to an integrated luminosity of 139 fb(-1) is presented. Events are selected if they contain a single lepton (electron or muon) or an opposite-sign lepton pair, in association with multiple jets. The events are categorised according to the number of jets and how likely these are to contain b-hadrons. A multivariate technique is then used to discriminate between signal and background events. The measured four-top-quark production cross section is found to be 26(-15)(+17) fb, with a corresponding observed (expected) significance of 1.9 (1.0) standard deviations over the background-only hypothesis. The result is combined with the previous measurement performed by the ATLAS Collaboration in the multilepton final state. The combined four-top-quark production cross section is measured to be 24(-6)(+7) fb, with a corresponding observed (expected) signal significance of 4.7 (2.6) standard deviations over the background-only predictions. It is consistent within 2.0 standard deviations with the Standard Model expectation of 12.0 +/- 2.4 fb. SN - 1029-8479 UR - https://arxiv.org/abs/2106.11683 UR - https://doi.org/10.1007/JHEP11(2021)118 DO - 10.1007/JHEP11(2021)118 LA - English N1 - WOS:000722987000001 ID - ATLASCollaborationAad_etal2021 ER -