Study of top-quark polarization in single-top-quark production at the CERN LHC

This paper complements the study of single top production at the LHC aiming to estimate the sensitivity of different observables to the magnitude of the effective couplings. In a previous paper the dominant $W$-gluon fusion mechanism was considered, while here we extend the analysis to the subdomina...

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Authors: Espriu, D. (Domènec), Manzano, J.
Format: article
Status:Published version
Publication Date:2002
Country:España
Institution:Universidad de Barcelona
Repository:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/12467
Online Access:https://hdl.handle.net/2445/12467
Access Level:Open access
Keyword:Partícules (Física nuclear)
Interaccions febles (Física nuclear)
Particles (Nuclear physics)
Weak interactions (Nuclear physics)
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spelling Study of top-quark polarization in single-top-quark production at the CERN LHCEspriu, D. (Domènec)Manzano, J.Partícules (Física nuclear)Interaccions febles (Física nuclear)Particles (Nuclear physics)Weak interactions (Nuclear physics)This paper complements the study of single top production at the LHC aiming to estimate the sensitivity of different observables to the magnitude of the effective couplings. In a previous paper the dominant $W$-gluon fusion mechanism was considered, while here we extend the analysis to the subdominant (10% with our set of experimental cuts) s-channel process. In order to distinguish left from right effective couplings it is required to consider polarized cross-sections and/or include $m_b$ effects. The spin of the top is accessible only indirectly by measuring the angular distribution of its decay products. We show that the presence of effective right-handed couplings implies necessarily that the top is not in a pure spin state. We discuss to what extent quantum interference terms can be neglected in the measurement and therefore simply multiply production and decay probabilities clasically. The coarsening involved in the measurement process makes this possible. We determine for each process the optimal spin basis where theoretical errors are minimized and, finally, discuss the sensitivity in the s-channel to the effective right-handed coupling. The results presented here are all analytical and include $m_b$ corrections. They are derived within the narrow width approximation for the top.The American Physical Society2002info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/12467Articles publicats en revistes (Física Quàntica i Astrofísica)reponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglésReproducció digital del document publicat en format paper, proporcionada per PROLA i http://dx.doi.org/10.1103/PhysRevD.66.114009Physical Review D, 2002, vol. 66, núm. 11, 114009-1-114009-13http://doi.org/10.1103/PhysRevD.66.114009(c) The American Physical Society, 2002info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/124672026-05-27T06:46:51Z
dc.title.none.fl_str_mv Study of top-quark polarization in single-top-quark production at the CERN LHC
title Study of top-quark polarization in single-top-quark production at the CERN LHC
spellingShingle Study of top-quark polarization in single-top-quark production at the CERN LHC
Espriu, D. (Domènec)
Partícules (Física nuclear)
Interaccions febles (Física nuclear)
Particles (Nuclear physics)
Weak interactions (Nuclear physics)
title_short Study of top-quark polarization in single-top-quark production at the CERN LHC
title_full Study of top-quark polarization in single-top-quark production at the CERN LHC
title_fullStr Study of top-quark polarization in single-top-quark production at the CERN LHC
title_full_unstemmed Study of top-quark polarization in single-top-quark production at the CERN LHC
title_sort Study of top-quark polarization in single-top-quark production at the CERN LHC
dc.creator.none.fl_str_mv Espriu, D. (Domènec)
Manzano, J.
author Espriu, D. (Domènec)
author_facet Espriu, D. (Domènec)
Manzano, J.
author_role author
author2 Manzano, J.
author2_role author
dc.subject.none.fl_str_mv Partícules (Física nuclear)
Interaccions febles (Física nuclear)
Particles (Nuclear physics)
Weak interactions (Nuclear physics)
topic Partícules (Física nuclear)
Interaccions febles (Física nuclear)
Particles (Nuclear physics)
Weak interactions (Nuclear physics)
description This paper complements the study of single top production at the LHC aiming to estimate the sensitivity of different observables to the magnitude of the effective couplings. In a previous paper the dominant $W$-gluon fusion mechanism was considered, while here we extend the analysis to the subdominant (10% with our set of experimental cuts) s-channel process. In order to distinguish left from right effective couplings it is required to consider polarized cross-sections and/or include $m_b$ effects. The spin of the top is accessible only indirectly by measuring the angular distribution of its decay products. We show that the presence of effective right-handed couplings implies necessarily that the top is not in a pure spin state. We discuss to what extent quantum interference terms can be neglected in the measurement and therefore simply multiply production and decay probabilities clasically. The coarsening involved in the measurement process makes this possible. We determine for each process the optimal spin basis where theoretical errors are minimized and, finally, discuss the sensitivity in the s-channel to the effective right-handed coupling. The results presented here are all analytical and include $m_b$ corrections. They are derived within the narrow width approximation for the top.
publishDate 2002
dc.date.none.fl_str_mv 2002
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/12467
url https://hdl.handle.net/2445/12467
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Reproducció digital del document publicat en format paper, proporcionada per PROLA i http://dx.doi.org/10.1103/PhysRevD.66.114009
Physical Review D, 2002, vol. 66, núm. 11, 114009-1-114009-13
http://doi.org/10.1103/PhysRevD.66.114009
dc.rights.none.fl_str_mv (c) The American Physical Society, 2002
info:eu-repo/semantics/openAccess
rights_invalid_str_mv (c) The American Physical Society, 2002
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv The American Physical Society
publisher.none.fl_str_mv The American Physical Society
dc.source.none.fl_str_mv Articles publicats en revistes (Física Quàntica i Astrofísica)
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,301603

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