Evidence for tt<overbar></mml:mover>tt<mml:mo stretchy="false"><overbar></mml:mover> production in the multilepton final state in proton-proton collisions at <mml:msqrt>s</mml:msqrt><mml:mo>=13 TeV with the ATLAS detector
Abstrakt
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).
Jet multiplicity, 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 24-6+7 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.