Observation of four-top-quark production in the multilepton final state with the ATLAS detector
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Archivos
Fecha
2023-07
Profesor/a Guía
Facultad/escuela
Idioma
en
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Título del volumen
Editor
Institute for Ionics
Nombre de Curso
Licencia CC
Attribution 4.0 International (CC BY 4.0)
Licencia CC
https://creativecommons.org/licenses/by/4.0/
Resumen
This paper presents the observation of four-top-quark (tt¯ tt¯) 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 TeV collected 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 the measured tt¯ tt¯ signal with respect to the standard model (SM) background-only hypothesis is 6.1 (4.3) standard deviations. The tt¯ tt¯ production cross section is measured to be 22.5-5.5+6.6 fb, consistent with the SM prediction 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 theory operator coefficients that affect tt¯ tt¯ production.
Notas
Indexación: Scopus.
Palabras clave
Boson, Partons, Higgs Bosons
Citación
European Physical Journal C Open Access Volume 83, Issue 6June 2023 Article number 496
DOI
10.1140/epjc/s10052-023-11573-0