Evidence for tt¯ tt¯ production in the multilepton final state in proton–proton collisions at√ s= 13 TeV with the ATLAS detector Aguilar Saavedra, Juan Antonio Atlas Collaboration Aad, G. A search is presented for four-top-quark production using an integrated luminosity of 139 fb−1 of proton– proton collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the LHC. Events are selected if they contain a same-sign lepton pair or at least three leptons (electrons or muons). Jetmultiplicity, jet flavour and event kinematics are used to separate signal from the background through a multivariate discriminant, and dedicated control regions are used to constrain the dominant backgrounds. The four-top-quark production cross section is measured to be 24+7 −6 fb. This corresponds to an observed (expected) significance with respect to the background-only hypothesis of 4.3 (2.4) standard deviations and provides evidence for this process. 2021-02-16T11:22:42Z 2021-02-16T11:22:42Z 2020-11 info:eu-repo/semantics/article Bogdanchikov, A. G., & ATLAS collaboration. (2020). Evidence for tt¯ tt¯ production in the multilepton final state in proton–proton collisions at√ s= 13 TeV with the ATLAS detector. European Physical Journal C, 80(11), 1085. [doi:10.1140/epjc/s10052-020-08509-3] http://hdl.handle.net/10481/66608 10.1140/epjc/s10052-020-08509-3 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España Springer