Search for tt¯ H/ A→ tt¯ tt¯ production in the multilepton final state in proton–proton collisions at √s = 13 TeV with the ATLAS detector

Detalhes bibliográficos
Autor(a) principal: Castro, Nuno Filipe
Data de Publicação: 2023
Outros Autores: Onofre, A., ATLAS Collaboration
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: https://hdl.handle.net/1822/87869
Resumo: A search for a new heavy scalar or pseudo-scalar Higgs boson (H/A) produced in association with a pair of top quarks, with the Higgs boson decaying into a pair of top quarks (H/A → tt¯) is reported. The search targets a final state with exactly two leptons with same-sign electric charges or at least three leptons. The analysed dataset corresponds to an integrated luminosity of 139 fb −1 of proton–proton collisions collected at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Two multivariate classifiers are used to separate the signal from the background. No significant excess of events over the Standard Model expectation is observed. The results are interpreted in the context of a type-II two-Higgs-doublet model. The observed (expected) upper limits at 95% confidence level on the tt¯ H/ A production cross-section times the branching ratio of H/A → tt¯ range between 14 (10) fb and 6 (5) fb for a heavy Higgs boson with mass between 400 GeV and 1000 GeV, respectively. Assuming that only one particle, either the scalar H or the pseudo-scalar A, contributes to the tt¯ tt¯ final state, values of tan β below 1.2 or 0.5 are excluded for a mass of 400 GeV or 1000 GeV, respectively. These exclusion ranges increase to tan β below 1.6 or 0.6 when both particles are considered. [Figure not available: see fulltext.]
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spelling Search for tt¯ H/ A→ tt¯ tt¯ production in the multilepton final state in proton–proton collisions at √s = 13 TeV with the ATLAS detectorBeyond Standard ModelHadron-Hadron ScatteringTop PhysicsCiências Naturais::Ciências FísicasA search for a new heavy scalar or pseudo-scalar Higgs boson (H/A) produced in association with a pair of top quarks, with the Higgs boson decaying into a pair of top quarks (H/A → tt¯) is reported. The search targets a final state with exactly two leptons with same-sign electric charges or at least three leptons. The analysed dataset corresponds to an integrated luminosity of 139 fb −1 of proton–proton collisions collected at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Two multivariate classifiers are used to separate the signal from the background. No significant excess of events over the Standard Model expectation is observed. The results are interpreted in the context of a type-II two-Higgs-doublet model. The observed (expected) upper limits at 95% confidence level on the tt¯ H/ A production cross-section times the branching ratio of H/A → tt¯ range between 14 (10) fb and 6 (5) fb for a heavy Higgs boson with mass between 400 GeV and 1000 GeV, respectively. Assuming that only one particle, either the scalar H or the pseudo-scalar A, contributes to the tt¯ tt¯ final state, values of tan β below 1.2 or 0.5 are excluded for a mass of 400 GeV or 1000 GeV, respectively. These exclusion ranges increase to tan β below 1.6 or 0.6 when both particles are considered. [Figure not available: see fulltext.]USDOE -U.S. Department of Energy(IN2P3-CNRS)info:eu-repo/semantics/publishedVersionSpringerUniversidade do MinhoCastro, Nuno FilipeOnofre, A.ATLAS Collaboration20232023-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/1822/87869engAad, G., Abbott, B., Abbott, D. C., Abeling, K., Abidi, S. H., Aboulhorma, A., . . . collaboration, A. (2023). Search for <i>t</i>(<i>t</i>)over-bar<i>H</i>/<i>A</i> → <i>t</i>(<i>t</i>)over-bar<i>t</i>(<i>t</i>)over-bar production in the multilepton final state in proton-proton collisions at √<i>s</i>=13 TeV with the ATLAS detector. Journal of High Energy Physics(7). doi: 10.1007/jhep07(2023)2031126-67081029-847910.1007/jhep07(2023)203https://link.springer.com/article/10.1007/JHEP07(2023)203info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-01-06T01:29:04Zoai:repositorium.sdum.uminho.pt:1822/87869Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T01:30:24.557374Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Search for tt¯ H/ A→ tt¯ tt¯ production in the multilepton final state in proton–proton collisions at √s = 13 TeV with the ATLAS detector
title Search for tt¯ H/ A→ tt¯ tt¯ production in the multilepton final state in proton–proton collisions at √s = 13 TeV with the ATLAS detector
spellingShingle Search for tt¯ H/ A→ tt¯ tt¯ production in the multilepton final state in proton–proton collisions at √s = 13 TeV with the ATLAS detector
Castro, Nuno Filipe
Beyond Standard Model
Hadron-Hadron Scattering
Top Physics
Ciências Naturais::Ciências Físicas
title_short Search for tt¯ H/ A→ tt¯ tt¯ production in the multilepton final state in proton–proton collisions at √s = 13 TeV with the ATLAS detector
title_full Search for tt¯ H/ A→ tt¯ tt¯ production in the multilepton final state in proton–proton collisions at √s = 13 TeV with the ATLAS detector
title_fullStr Search for tt¯ H/ A→ tt¯ tt¯ production in the multilepton final state in proton–proton collisions at √s = 13 TeV with the ATLAS detector
title_full_unstemmed Search for tt¯ H/ A→ tt¯ tt¯ production in the multilepton final state in proton–proton collisions at √s = 13 TeV with the ATLAS detector
title_sort Search for tt¯ H/ A→ tt¯ tt¯ production in the multilepton final state in proton–proton collisions at √s = 13 TeV with the ATLAS detector
author Castro, Nuno Filipe
author_facet Castro, Nuno Filipe
Onofre, A.
ATLAS Collaboration
author_role author
author2 Onofre, A.
ATLAS Collaboration
author2_role author
author
dc.contributor.none.fl_str_mv Universidade do Minho
dc.contributor.author.fl_str_mv Castro, Nuno Filipe
Onofre, A.
ATLAS Collaboration
dc.subject.por.fl_str_mv Beyond Standard Model
Hadron-Hadron Scattering
Top Physics
Ciências Naturais::Ciências Físicas
topic Beyond Standard Model
Hadron-Hadron Scattering
Top Physics
Ciências Naturais::Ciências Físicas
description A search for a new heavy scalar or pseudo-scalar Higgs boson (H/A) produced in association with a pair of top quarks, with the Higgs boson decaying into a pair of top quarks (H/A → tt¯) is reported. The search targets a final state with exactly two leptons with same-sign electric charges or at least three leptons. The analysed dataset corresponds to an integrated luminosity of 139 fb −1 of proton–proton collisions collected at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Two multivariate classifiers are used to separate the signal from the background. No significant excess of events over the Standard Model expectation is observed. The results are interpreted in the context of a type-II two-Higgs-doublet model. The observed (expected) upper limits at 95% confidence level on the tt¯ H/ A production cross-section times the branching ratio of H/A → tt¯ range between 14 (10) fb and 6 (5) fb for a heavy Higgs boson with mass between 400 GeV and 1000 GeV, respectively. Assuming that only one particle, either the scalar H or the pseudo-scalar A, contributes to the tt¯ tt¯ final state, values of tan β below 1.2 or 0.5 are excluded for a mass of 400 GeV or 1000 GeV, respectively. These exclusion ranges increase to tan β below 1.6 or 0.6 when both particles are considered. [Figure not available: see fulltext.]
publishDate 2023
dc.date.none.fl_str_mv 2023
2023-01-01T00:00:00Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv https://hdl.handle.net/1822/87869
url https://hdl.handle.net/1822/87869
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Aad, G., Abbott, B., Abbott, D. C., Abeling, K., Abidi, S. H., Aboulhorma, A., . . . collaboration, A. (2023). Search for <i>t</i>(<i>t</i>)over-bar<i>H</i>/<i>A</i> → <i>t</i>(<i>t</i>)over-bar<i>t</i>(<i>t</i>)over-bar production in the multilepton final state in proton-proton collisions at √<i>s</i>=13 TeV with the ATLAS detector. Journal of High Energy Physics(7). doi: 10.1007/jhep07(2023)203
1126-6708
1029-8479
10.1007/jhep07(2023)203
https://link.springer.com/article/10.1007/JHEP07(2023)203
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Springer
publisher.none.fl_str_mv Springer
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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instname_str Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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