Measurement of cross sections and leptonic forward-backward asymmetries at the Z pole and determination of electroweak parameters

Autores
Dova, María Teresa; L3 Collaboration
Año de publicación
1994
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We report on the measurement of the leptonic and hadronic cross sections and leptonic forward-backward asymmetries at theZ peak with the L3 detector at LEP. The total luminosity of 40.8 pb−1 collected in the years 1990, 1991 and 1992 corresponds to 1.09·106 hadronic and 0.98·105 leptonic Z decays observed. These data allow us to determine the electroweak parameters. From the cross sections we derive the properties of the Z boson: MZ=91195 ± 9 MeVΓZ=2494 ± 10 MeV Γhad=1748 ± 10 MeVΓ=83.49 ± 0.46MeV assuming lepton universality. We obtain an invisible width of Γinv=496.5 ± 7.9 MeV which, in the Standard Model, corresponds to a number of light neutrino species of Nv=2.981 ± 0.050. Using also the three leptonic forward-backward asymmetries and the average tau polarization, we determine the effective vector and axial-vector coupling constants of the neutral weak current to charged leptons to be: g¯ℓv=−0.0378+0.0045−0.0042 g¯ℓA=−0.4998 ± 0.0014. Within the framework of the Standard Model, and including our measurements of the Z→b¯b forward-backward asymmetry and partial decay width, we derive an effective electroweak mixing angle of sin2¯θW=0.2326 ± 0.0012 . We obtain an estimate for the strong coupling constant, αS=0.142 ± 0.013 and for the top-quark mass,mt =158+32−40 ± 19(Higgs) GeV, where the second error arises due to the uncertainty in the Higgs-boson mass.
Facultad de Ciencias Exactas
Materia
Ciencias Exactas
Física
Partículas Elementales
L3 detector
la̵rge hadron collider
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/81046

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oai_identifier_str oai:sedici.unlp.edu.ar:10915/81046
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Measurement of cross sections and leptonic forward-backward asymmetries at the Z pole and determination of electroweak parametersDova, María TeresaL3 CollaborationCiencias ExactasFísicaPartículas ElementalesL3 detectorla̵rge hadron colliderWe report on the measurement of the leptonic and hadronic cross sections and leptonic forward-backward asymmetries at theZ peak with the L3 detector at LEP. The total luminosity of 40.8 pb<sup>−1</sup> collected in the years 1990, 1991 and 1992 corresponds to 1.09·10<sup>6</sup> hadronic and 0.98·10<sup>5</sup> leptonic Z decays observed. These data allow us to determine the electroweak parameters. From the cross sections we derive the properties of the Z boson: M<sub>Z</sub>=91195 ± 9 MeVΓ<sub>Z</sub>=2494 ± 10 MeV Γ<sub>had</sub>=1748 ± 10 MeVΓ<sub>ℓ</sub>=83.49 ± 0.46MeV assuming lepton universality. We obtain an invisible width of Γ<sub>inv</sub>=496.5 ± 7.9 MeV which, in the Standard Model, corresponds to a number of light neutrino species of Nv=2.981 ± 0.050. Using also the three leptonic forward-backward asymmetries and the average tau polarization, we determine the effective vector and axial-vector coupling constants of the neutral weak current to charged leptons to be: g¯ℓv=−0.0378<sup>+0.0045</sup><sub>−0.0042</sub> g¯ℓA=−0.4998 ± 0.0014. Within the framework of the Standard Model, and including our measurements of the Z→b¯b forward-backward asymmetry and partial decay width, we derive an effective electroweak mixing angle of sin<sup>2</sup>¯θ<sub>W</sub>=0.2326 ± 0.0012 . We obtain an estimate for the strong coupling constant, α<sub>S</sub>=0.142 ± 0.013 and for the top-quark mass,m<sub>t</sub> =158<sup>+32</sup><sub>−40</sub> ± 19(Higgs) GeV, where the second error arises due to the uncertainty in the Higgs-boson mass.Facultad de Ciencias Exactas1994-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf551-573http://sedici.unlp.edu.ar/handle/10915/81046enginfo:eu-repo/semantics/altIdentifier/issn/0170-9739info:eu-repo/semantics/altIdentifier/doi/10.1007/BF01574160info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:15:01Zoai:sedici.unlp.edu.ar:10915/81046Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:15:01.84SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Measurement of cross sections and leptonic forward-backward asymmetries at the Z pole and determination of electroweak parameters
title Measurement of cross sections and leptonic forward-backward asymmetries at the Z pole and determination of electroweak parameters
spellingShingle Measurement of cross sections and leptonic forward-backward asymmetries at the Z pole and determination of electroweak parameters
Dova, María Teresa
Ciencias Exactas
Física
Partículas Elementales
L3 detector
la̵rge hadron collider
title_short Measurement of cross sections and leptonic forward-backward asymmetries at the Z pole and determination of electroweak parameters
title_full Measurement of cross sections and leptonic forward-backward asymmetries at the Z pole and determination of electroweak parameters
title_fullStr Measurement of cross sections and leptonic forward-backward asymmetries at the Z pole and determination of electroweak parameters
title_full_unstemmed Measurement of cross sections and leptonic forward-backward asymmetries at the Z pole and determination of electroweak parameters
title_sort Measurement of cross sections and leptonic forward-backward asymmetries at the Z pole and determination of electroweak parameters
dc.creator.none.fl_str_mv Dova, María Teresa
L3 Collaboration
author Dova, María Teresa
author_facet Dova, María Teresa
L3 Collaboration
author_role author
author2 L3 Collaboration
author2_role author
dc.subject.none.fl_str_mv Ciencias Exactas
Física
Partículas Elementales
L3 detector
la̵rge hadron collider
topic Ciencias Exactas
Física
Partículas Elementales
L3 detector
la̵rge hadron collider
dc.description.none.fl_txt_mv We report on the measurement of the leptonic and hadronic cross sections and leptonic forward-backward asymmetries at theZ peak with the L3 detector at LEP. The total luminosity of 40.8 pb<sup>−1</sup> collected in the years 1990, 1991 and 1992 corresponds to 1.09·10<sup>6</sup> hadronic and 0.98·10<sup>5</sup> leptonic Z decays observed. These data allow us to determine the electroweak parameters. From the cross sections we derive the properties of the Z boson: M<sub>Z</sub>=91195 ± 9 MeVΓ<sub>Z</sub>=2494 ± 10 MeV Γ<sub>had</sub>=1748 ± 10 MeVΓ<sub>ℓ</sub>=83.49 ± 0.46MeV assuming lepton universality. We obtain an invisible width of Γ<sub>inv</sub>=496.5 ± 7.9 MeV which, in the Standard Model, corresponds to a number of light neutrino species of Nv=2.981 ± 0.050. Using also the three leptonic forward-backward asymmetries and the average tau polarization, we determine the effective vector and axial-vector coupling constants of the neutral weak current to charged leptons to be: g¯ℓv=−0.0378<sup>+0.0045</sup><sub>−0.0042</sub> g¯ℓA=−0.4998 ± 0.0014. Within the framework of the Standard Model, and including our measurements of the Z→b¯b forward-backward asymmetry and partial decay width, we derive an effective electroweak mixing angle of sin<sup>2</sup>¯θ<sub>W</sub>=0.2326 ± 0.0012 . We obtain an estimate for the strong coupling constant, α<sub>S</sub>=0.142 ± 0.013 and for the top-quark mass,m<sub>t</sub> =158<sup>+32</sup><sub>−40</sub> ± 19(Higgs) GeV, where the second error arises due to the uncertainty in the Higgs-boson mass.
Facultad de Ciencias Exactas
description We report on the measurement of the leptonic and hadronic cross sections and leptonic forward-backward asymmetries at theZ peak with the L3 detector at LEP. The total luminosity of 40.8 pb<sup>−1</sup> collected in the years 1990, 1991 and 1992 corresponds to 1.09·10<sup>6</sup> hadronic and 0.98·10<sup>5</sup> leptonic Z decays observed. These data allow us to determine the electroweak parameters. From the cross sections we derive the properties of the Z boson: M<sub>Z</sub>=91195 ± 9 MeVΓ<sub>Z</sub>=2494 ± 10 MeV Γ<sub>had</sub>=1748 ± 10 MeVΓ<sub>ℓ</sub>=83.49 ± 0.46MeV assuming lepton universality. We obtain an invisible width of Γ<sub>inv</sub>=496.5 ± 7.9 MeV which, in the Standard Model, corresponds to a number of light neutrino species of Nv=2.981 ± 0.050. Using also the three leptonic forward-backward asymmetries and the average tau polarization, we determine the effective vector and axial-vector coupling constants of the neutral weak current to charged leptons to be: g¯ℓv=−0.0378<sup>+0.0045</sup><sub>−0.0042</sub> g¯ℓA=−0.4998 ± 0.0014. Within the framework of the Standard Model, and including our measurements of the Z→b¯b forward-backward asymmetry and partial decay width, we derive an effective electroweak mixing angle of sin<sup>2</sup>¯θ<sub>W</sub>=0.2326 ± 0.0012 . We obtain an estimate for the strong coupling constant, α<sub>S</sub>=0.142 ± 0.013 and for the top-quark mass,m<sub>t</sub> =158<sup>+32</sup><sub>−40</sub> ± 19(Higgs) GeV, where the second error arises due to the uncertainty in the Higgs-boson mass.
publishDate 1994
dc.date.none.fl_str_mv 1994-12
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/10915/81046
url http://sedici.unlp.edu.ar/handle/10915/81046
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0170-9739
info:eu-repo/semantics/altIdentifier/doi/10.1007/BF01574160
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
551-573
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
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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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