Search for flavour-changing neutral current top-quark decays t → qZ in proton-proton collisions at √s=13 TeV with the ATLAS detector

A search for flavour-changing neutral-current processes in top-quark decays is presented. Data collected with the ATLAS detector from proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of s=13 TeV, corresponding to an integrated luminosity of 36.1 fb −1 , are analysed....

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Guardado en:
Detalles Bibliográficos
Publicado: 2018
Materias:
Hadron-Hadron scattering (experiments)
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_11266708_v2018_n7_p_Aaboud
http://hdl.handle.net/20.500.12110/paper_11266708_v2018_n7_p_Aaboud
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_11266708_v2018_n7_p_Aaboud
record_format dspace
spelling paper:paper_11266708_v2018_n7_p_Aaboud2023-06-08T16:08:59Z Search for flavour-changing neutral current top-quark decays t → qZ in proton-proton collisions at √s=13 TeV with the ATLAS detector Hadron-Hadron scattering (experiments) A search for flavour-changing neutral-current processes in top-quark decays is presented. Data collected with the ATLAS detector from proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of s=13 TeV, corresponding to an integrated luminosity of 36.1 fb −1 , are analysed. The search is performed using top-quark pair events, with one top quark decaying through the t → qZ (q = u, c) flavour-changing neutral-current channel, and the other through the dominant Standard Model mode t → bW. Only Z boson decays into charged leptons and leptonic W boson decays are considered as signal. Consequently, the final-state topology is characterized by the presence of three isolated charged leptons (electrons or muons), at least two jets, one of the jets originating from a b-quark, and missing transverse momentum from the undetected neutrino. The data are consistent with Standard Model background contributions, and at 95% confidence level the search sets observed (expected) upper limits of 1.7 × 10 −4 (2.4 × 10 −4 ) on the t → uZ branching ratio and 2.4 × 10 −4 (3.2 × 10 −4 ) on the t → cZ branching ratio, constituting the most stringent limits to date.[Figure not available: see fulltext.]. © 2018, The Author(s). 2018 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_11266708_v2018_n7_p_Aaboud http://hdl.handle.net/20.500.12110/paper_11266708_v2018_n7_p_Aaboud
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Hadron-Hadron scattering (experiments)
spellingShingle Hadron-Hadron scattering (experiments)
Search for flavour-changing neutral current top-quark decays t → qZ in proton-proton collisions at √s=13 TeV with the ATLAS detector
topic_facet Hadron-Hadron scattering (experiments)
description A search for flavour-changing neutral-current processes in top-quark decays is presented. Data collected with the ATLAS detector from proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of s=13 TeV, corresponding to an integrated luminosity of 36.1 fb −1 , are analysed. The search is performed using top-quark pair events, with one top quark decaying through the t → qZ (q = u, c) flavour-changing neutral-current channel, and the other through the dominant Standard Model mode t → bW. Only Z boson decays into charged leptons and leptonic W boson decays are considered as signal. Consequently, the final-state topology is characterized by the presence of three isolated charged leptons (electrons or muons), at least two jets, one of the jets originating from a b-quark, and missing transverse momentum from the undetected neutrino. The data are consistent with Standard Model background contributions, and at 95% confidence level the search sets observed (expected) upper limits of 1.7 × 10 −4 (2.4 × 10 −4 ) on the t → uZ branching ratio and 2.4 × 10 −4 (3.2 × 10 −4 ) on the t → cZ branching ratio, constituting the most stringent limits to date.[Figure not available: see fulltext.]. © 2018, The Author(s).
title Search for flavour-changing neutral current top-quark decays t → qZ in proton-proton collisions at √s=13 TeV with the ATLAS detector
title_short Search for flavour-changing neutral current top-quark decays t → qZ in proton-proton collisions at √s=13 TeV with the ATLAS detector
title_full Search for flavour-changing neutral current top-quark decays t → qZ in proton-proton collisions at √s=13 TeV with the ATLAS detector
title_fullStr Search for flavour-changing neutral current top-quark decays t → qZ in proton-proton collisions at √s=13 TeV with the ATLAS detector
title_full_unstemmed Search for flavour-changing neutral current top-quark decays t → qZ in proton-proton collisions at √s=13 TeV with the ATLAS detector
title_sort search for flavour-changing neutral current top-quark decays t → qz in proton-proton collisions at √s=13 tev with the atlas detector
publishDate 2018
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_11266708_v2018_n7_p_Aaboud
http://hdl.handle.net/20.500.12110/paper_11266708_v2018_n7_p_Aaboud
_version_ 1768541999760146432

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