Evidence for the associated production of a W boson and a top quark in ATLAS at √s=7TeV

This Letter presents evidence for the associated production of a W boson and a top quark using 2.05 fb −1 of pp collision data at s=7TeV accumulated with the ATLAS detector at the LHC. The analysis is based on the selection of the dileptonic final states with events featuring two isolated leptons, e...

Descripción completa

Guardado en:
Detalles Bibliográficos
Publicado: 2012
Materias:
ATLAS
Single top-quark
Top quark
W+t
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03702693_v716_n1_p142_Aad
http://hdl.handle.net/20.500.12110/paper_03702693_v716_n1_p142_Aad
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_03702693_v716_n1_p142_Aad
record_format dspace
spelling paper:paper_03702693_v716_n1_p142_Aad2023-06-08T15:37:05Z Evidence for the associated production of a W boson and a top quark in ATLAS at √s=7TeV ATLAS Single top-quark Top quark W+t This Letter presents evidence for the associated production of a W boson and a top quark using 2.05 fb −1 of pp collision data at s=7TeV accumulated with the ATLAS detector at the LHC. The analysis is based on the selection of the dileptonic final states with events featuring two isolated leptons, electron or muon, with significant transverse missing momentum and at least one jet. An approach based on boosted decision trees has been developed to improve the discrimination of single top-quark Wt events from background. A template fit to the final classifier distributions is performed to determine the cross-section. The result is incompatible with the background-only hypothesis at the 3.3σ level, the expected sensitivity assuming the Standard Model production rate being 3.4σ. The corresponding cross-section is determined and found to be σ Wt =16.8±2.9 (stat)±4.9 (syst) pb, in good agreement with the Standard Model expectation. From this result the CKM matrix element |V tb |=1.03 −0.19 +0.16 is derived assuming that the Wt production through |V ts | and |V td | is small. © 2012 CERN 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03702693_v716_n1_p142_Aad http://hdl.handle.net/20.500.12110/paper_03702693_v716_n1_p142_Aad
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic ATLAS
Single top-quark
Top quark
W+t
spellingShingle ATLAS
Single top-quark
Top quark
W+t
Evidence for the associated production of a W boson and a top quark in ATLAS at √s=7TeV
topic_facet ATLAS
Single top-quark
Top quark
W+t
description This Letter presents evidence for the associated production of a W boson and a top quark using 2.05 fb −1 of pp collision data at s=7TeV accumulated with the ATLAS detector at the LHC. The analysis is based on the selection of the dileptonic final states with events featuring two isolated leptons, electron or muon, with significant transverse missing momentum and at least one jet. An approach based on boosted decision trees has been developed to improve the discrimination of single top-quark Wt events from background. A template fit to the final classifier distributions is performed to determine the cross-section. The result is incompatible with the background-only hypothesis at the 3.3σ level, the expected sensitivity assuming the Standard Model production rate being 3.4σ. The corresponding cross-section is determined and found to be σ Wt =16.8±2.9 (stat)±4.9 (syst) pb, in good agreement with the Standard Model expectation. From this result the CKM matrix element |V tb |=1.03 −0.19 +0.16 is derived assuming that the Wt production through |V ts | and |V td | is small. © 2012 CERN
title Evidence for the associated production of a W boson and a top quark in ATLAS at √s=7TeV
title_short Evidence for the associated production of a W boson and a top quark in ATLAS at √s=7TeV
title_full Evidence for the associated production of a W boson and a top quark in ATLAS at √s=7TeV
title_fullStr Evidence for the associated production of a W boson and a top quark in ATLAS at √s=7TeV
title_full_unstemmed Evidence for the associated production of a W boson and a top quark in ATLAS at √s=7TeV
title_sort evidence for the associated production of a w boson and a top quark in atlas at √s=7tev
publishDate 2012
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03702693_v716_n1_p142_Aad
http://hdl.handle.net/20.500.12110/paper_03702693_v716_n1_p142_Aad
_version_ 1768542460699475968

Ejemplares similares