Observation of four-top-quark production in the multilepton final state with the ATLAS detector
Date
2023
Authors
Aad, G.
Abbott, B.
Abeling, K.
Abicht, N.J.
Abidi, S.H.
Aboulhorma, A.
Abramowicz, H.
Abreu, H.
Abulaiti, Y.
Hoffman, A.C.A.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
European Physical Journal C, 2023; 83(6):496-1-496-35
Statement of Responsibility
Conference Name
Abstract
This paper presents the observation of four-topquark (t ¯tt ¯t) production in proton-proton collisions at the LHC. The analysis is performed using an integrated luminosity of 140 fb−1 at a centre-of-mass energy of 13 TeVcollected using the ATLAS detector. Events containing two leptons with the same electric charge or at least three leptons (electrons or muons) are selected. Event kinematics are used to separate signal from background through a multivariate discriminant, and dedicated control regions are used to constrain the dominant backgrounds. The observed (expected) significance of themeasured t ¯tt ¯t signal with respect to the standard model (SM) background-only hypothesis is 6.1 (4.3) standard deviations. The t ¯tt ¯t production cross section is measured to be 22.5+6.6 −5.5 fb, consistent with the SMprediction of 12.0 ± 2.4 fb within 1.8 standard deviations. Data are also used to set limits on the three-top-quark production cross section, being an irreducible background not measured previously, and to constrain the top-Higgs Yukawa coupling and effective field.
School/Discipline
Dissertation Note
Provenance
Description
Access Status
Rights
© CERN for the benefit of the ATLAS collaboration 2023. This article is licensed under a Creative Commons Attribution 4.0 International License,which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecomm ons.org/licenses/by/4.0/.