Measurement of the W boson polarisation in t¯t events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS

Autores
Alconada Verzini, María Josefina; Alonso, Francisco; Arduh, Francisco Anuar; Dova, María Teresa; Hoya, Joaquín; Monticelli, Fernando Gabriel; Wahlberg, Hernán Pablo; The ATLAS Collaboration
Año de publicación
2017
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
This paper presents a measurement of the polarisation of W bosons from t¯t decays, reconstructed in events with one high-pT lepton and at least four jets. Data from pp collisions at the LHC were collected at √s = 8 TeV and correspond to an integrated luminosity of 20.2 fb−1. The angle θ* between the b-quark from the top quark decay and a direct W boson decay product in the W boson rest frame is sensitive to the W boson polarisation. Two different W decay products are used as polarisation analysers: the charged lepton and the down-type quark for the leptonically and hadronically decaying W boson, respectively. The most precise measurement of the W boson polarisation via the distribution of cos θ* is obtained using the leptonic analyser and events in which at least two of the jets are tagged as b-quark jets. The fitted fractions of longitudinal, left- and right-handed polarisation states are F0 = 0.709 ± 0.019, FL = 0.299 ± 0.015 and FR = −0.008 ± 0.014, and are the most precisely measured W boson polarisation fractions to date. Limits on anomalous couplings of the W tb vertex are set.
Facultad de Ciencias Exactas
Materia
Ciencias Exactas
Física
w boson
Polarización
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/81860
Acceder
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oai_identifier_str oai:sedici.unlp.edu.ar:10915/81860
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Measurement of the W boson polarisation in t¯t events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLASAlconada Verzini, María JosefinaAlonso, FranciscoArduh, Francisco AnuarDova, María TeresaHoya, JoaquínMonticelli, Fernando GabrielWahlberg, Hernán PabloThe ATLAS CollaborationCiencias ExactasFísicaw bosonPolarizaciónThis paper presents a measurement of the polarisation of W bosons from t¯t decays, reconstructed in events with one high-p<sub>T</sub> lepton and at least four jets. Data from pp collisions at the LHC were collected at √s = 8 TeV and correspond to an integrated luminosity of 20.2 fb<sup>−1</sup>. The angle θ* between the b-quark from the top quark decay and a direct W boson decay product in the W boson rest frame is sensitive to the W boson polarisation. Two different W decay products are used as polarisation analysers: the charged lepton and the down-type quark for the leptonically and hadronically decaying W boson, respectively. The most precise measurement of the W boson polarisation via the distribution of cos θ* is obtained using the leptonic analyser and events in which at least two of the jets are tagged as b-quark jets. The fitted fractions of longitudinal, left- and right-handed polarisation states are F<sub>0</sub> = 0.709 ± 0.019, F<sub>L</sub> = 0.299 ± 0.015 and F<sub>R</sub> = −0.008 ± 0.014, and are the most precisely measured W boson polarisation fractions to date. Limits on anomalous couplings of the W tb vertex are set.Facultad de Ciencias Exactas2017-04-26info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articulotext/plainhttp://sedici.unlp.edu.ar/handle/10915/81860enginfo:eu-repo/semantics/altIdentifier/issn/1434-6052info:eu-repo/semantics/altIdentifier/doi/10.1140/epjc/s10052-017-4819-4info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:15:17Zoai:sedici.unlp.edu.ar:10915/81860Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:15:17.426SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Measurement of the W boson polarisation in t¯t events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS
title Measurement of the W boson polarisation in t¯t events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS
spellingShingle Measurement of the W boson polarisation in t¯t events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS
Alconada Verzini, María Josefina
Ciencias Exactas
Física
w boson
Polarización
title_short Measurement of the W boson polarisation in t¯t events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS
title_full Measurement of the W boson polarisation in t¯t events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS
title_fullStr Measurement of the W boson polarisation in t¯t events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS
title_full_unstemmed Measurement of the W boson polarisation in t¯t events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS
title_sort Measurement of the W boson polarisation in t¯t events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS
dc.creator.none.fl_str_mv Alconada Verzini, María Josefina
Alonso, Francisco
Arduh, Francisco Anuar
Dova, María Teresa
Hoya, Joaquín
Monticelli, Fernando Gabriel
Wahlberg, Hernán Pablo
The ATLAS Collaboration
author Alconada Verzini, María Josefina
author_facet Alconada Verzini, María Josefina
Alonso, Francisco
Arduh, Francisco Anuar
Dova, María Teresa
Hoya, Joaquín
Monticelli, Fernando Gabriel
Wahlberg, Hernán Pablo
The ATLAS Collaboration
author_role author
author2 Alonso, Francisco
Arduh, Francisco Anuar
Dova, María Teresa
Hoya, Joaquín
Monticelli, Fernando Gabriel
Wahlberg, Hernán Pablo
The ATLAS Collaboration
author2_role author
author
author
author
author
author
author
dc.subject.none.fl_str_mv Ciencias Exactas
Física
w boson
Polarización
topic Ciencias Exactas
Física
w boson
Polarización
dc.description.none.fl_txt_mv This paper presents a measurement of the polarisation of W bosons from t¯t decays, reconstructed in events with one high-p<sub>T</sub> lepton and at least four jets. Data from pp collisions at the LHC were collected at √s = 8 TeV and correspond to an integrated luminosity of 20.2 fb<sup>−1</sup>. The angle θ* between the b-quark from the top quark decay and a direct W boson decay product in the W boson rest frame is sensitive to the W boson polarisation. Two different W decay products are used as polarisation analysers: the charged lepton and the down-type quark for the leptonically and hadronically decaying W boson, respectively. The most precise measurement of the W boson polarisation via the distribution of cos θ* is obtained using the leptonic analyser and events in which at least two of the jets are tagged as b-quark jets. The fitted fractions of longitudinal, left- and right-handed polarisation states are F<sub>0</sub> = 0.709 ± 0.019, F<sub>L</sub> = 0.299 ± 0.015 and F<sub>R</sub> = −0.008 ± 0.014, and are the most precisely measured W boson polarisation fractions to date. Limits on anomalous couplings of the W tb vertex are set.
Facultad de Ciencias Exactas
description This paper presents a measurement of the polarisation of W bosons from t¯t decays, reconstructed in events with one high-p<sub>T</sub> lepton and at least four jets. Data from pp collisions at the LHC were collected at √s = 8 TeV and correspond to an integrated luminosity of 20.2 fb<sup>−1</sup>. The angle θ* between the b-quark from the top quark decay and a direct W boson decay product in the W boson rest frame is sensitive to the W boson polarisation. Two different W decay products are used as polarisation analysers: the charged lepton and the down-type quark for the leptonically and hadronically decaying W boson, respectively. The most precise measurement of the W boson polarisation via the distribution of cos θ* is obtained using the leptonic analyser and events in which at least two of the jets are tagged as b-quark jets. The fitted fractions of longitudinal, left- and right-handed polarisation states are F<sub>0</sub> = 0.709 ± 0.019, F<sub>L</sub> = 0.299 ± 0.015 and F<sub>R</sub> = −0.008 ± 0.014, and are the most precisely measured W boson polarisation fractions to date. Limits on anomalous couplings of the W tb vertex are set.
publishDate 2017
dc.date.none.fl_str_mv 2017-04-26
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/81860
url http://sedici.unlp.edu.ar/handle/10915/81860
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/1434-6052
info:eu-repo/semantics/altIdentifier/doi/10.1140/epjc/s10052-017-4819-4
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
dc.format.none.fl_str_mv text/plain
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
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score 13.070432

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