Measurement of electroweak parameters from hadronic and leptonic decays of the Z<sup>0</sup>

Autores
Dova, María Teresa; L3 Collaboration
Año de publicación
1991
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We have studied the reactions e+e−→hadrons, e+e−, μ+ μ− and τ+τ−, in the energy range 88.2 ≦ √s ≦ 94.2 GeV. A total luminosity of 5.5 pb−1, corresponding to approximately 115000 hadronic and 10000 leptonic Z0 decays, has been recorded with the L3 detector. From a simultaneous fit to all of our measured cross section data, we obtain assuming lepton universality: Mz = 91.181 ± 0.010 ± 0.02 (LEP) GeV, Γz = 2501 ± 17 MeV, Γhad= 1742 ± 19 MeV, Γt = 83.6 ± 0.8 MeV. If we do not assume lepton universality, we obtain for the partial decay widths of the Z0 into e+e−, μ+μ− and τ+ τ−: Γe = 83.3 ± 1.1 MeV, Γμ = 84.5 ± 2.0 MeV, Γτ = 84.0 ± 2.7 MeV. From the measured ratio of the invisible and the leptonic decay widths of the Z0, we determine the number of light neutrino species to be Nv =3.05±0.10. We include our measurements of the forward-backward asymmetry for the leptonic channels in a fit to determine the vector and axial-vector neutral current coupling constants of charged leptons to the Z0. We obtain g¯V = −0.046+0.015−0.012 and g¯A = −0.500 ± 0.003. In the framework of the Standard Model, we estimate the top quark mass to be mt =193+52−69 ± 16 (Higgs) GeV, and we derive a value for the weak mixing angle of sin2θW ≡ 1 − (MW/MZ)2 = 0.222 ± 0.008, corresponding to an effective weak mixing angle of sin2θ¯W = 0.2315 ± 0.0025.
Facultad de Ciencias Exactas
Materia
Ciencias Exactas
Física
large electron positron collider
Partículas Elementales
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:10915/81060

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oai_identifier_str oai:sedici.unlp.edu.ar:10915/81060
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Measurement of electroweak parameters from hadronic and leptonic decays of the Z<sup>0</sup>Dova, María TeresaL3 CollaborationCiencias ExactasFísicalarge electron positron colliderPartículas ElementalesWe have studied the reactions e+e−→hadrons, e+e−, μ+ μ− and τ+τ−, in the energy range 88.2 ≦ √s ≦ 94.2 GeV. A total luminosity of 5.5 pb<sup>−1</sup>, corresponding to approximately 115000 hadronic and 10000 leptonic Z<sup>0</sup> decays, has been recorded with the L3 detector. From a simultaneous fit to all of our measured cross section data, we obtain assuming lepton universality: M<sub>z</sub> = 91.181 ± 0.010 ± 0.02 (LEP) GeV, Γ<sub>z</sub> = 2501 ± 17 MeV, Γ<sub>had</sub>= 1742 ± 19 MeV, Γ<sub>t</sub> = 83.6 ± 0.8 MeV. If we do not assume lepton universality, we obtain for the partial decay widths of the Z<sup>0</sup> into e+e−, μ+μ− and τ+ τ−: Γ<sub>e</sub> = 83.3 ± 1.1 MeV, Γ<sub>μ</sub> = 84.5 ± 2.0 MeV, Γ<sub>τ</sub> = 84.0 ± 2.7 MeV. From the measured ratio of the invisible and the leptonic decay widths of the Z<sup>0</sup>, we determine the number of light neutrino species to be Nv =3.05±0.10. We include our measurements of the forward-backward asymmetry for the leptonic channels in a fit to determine the vector and axial-vector neutral current coupling constants of charged leptons to the Z<sup>0</sup>. We obtain g¯<sub>V</sub> = −0.046<sup>+0.015</sup><sub>−0.012</sub> and g¯<sub>A</sub> = −0.500 ± 0.003. In the framework of the Standard Model, we estimate the top quark mass to be m<sub>t</sub> =193<sup>+52</sup><sub>−69</sub> ± 16 (Higgs) GeV, and we derive a value for the weak mixing angle of sin<sup>2</sup>θ<sub>W</sub> ≡ 1 − (M<sub>W</sub>/M<sub>Z</sub>)<sup>2</sup> = 0.222 ± 0.008, corresponding to an effective weak mixing angle of sin<sup>2</sup>θ¯<sub>W</sub> = 0.2315 ± 0.0025.Facultad de Ciencias Exactas1991-06info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf179-203http://sedici.unlp.edu.ar/handle/10915/81060enginfo:eu-repo/semantics/altIdentifier/issn/0170-9739info:eu-repo/semantics/altIdentifier/doi/10.1007/BF01475788info: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:10915/81060Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:15:01.865SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Measurement of electroweak parameters from hadronic and leptonic decays of the Z<sup>0</sup>
title Measurement of electroweak parameters from hadronic and leptonic decays of the Z<sup>0</sup>
spellingShingle Measurement of electroweak parameters from hadronic and leptonic decays of the Z<sup>0</sup>
Dova, María Teresa
Ciencias Exactas
Física
large electron positron collider
Partículas Elementales
title_short Measurement of electroweak parameters from hadronic and leptonic decays of the Z<sup>0</sup>
title_full Measurement of electroweak parameters from hadronic and leptonic decays of the Z<sup>0</sup>
title_fullStr Measurement of electroweak parameters from hadronic and leptonic decays of the Z<sup>0</sup>
title_full_unstemmed Measurement of electroweak parameters from hadronic and leptonic decays of the Z<sup>0</sup>
title_sort Measurement of electroweak parameters from hadronic and leptonic decays of the Z<sup>0</sup>
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
large electron positron collider
Partículas Elementales
topic Ciencias Exactas
Física
large electron positron collider
Partículas Elementales
dc.description.none.fl_txt_mv We have studied the reactions e+e−→hadrons, e+e−, μ+ μ− and τ+τ−, in the energy range 88.2 ≦ √s ≦ 94.2 GeV. A total luminosity of 5.5 pb<sup>−1</sup>, corresponding to approximately 115000 hadronic and 10000 leptonic Z<sup>0</sup> decays, has been recorded with the L3 detector. From a simultaneous fit to all of our measured cross section data, we obtain assuming lepton universality: M<sub>z</sub> = 91.181 ± 0.010 ± 0.02 (LEP) GeV, Γ<sub>z</sub> = 2501 ± 17 MeV, Γ<sub>had</sub>= 1742 ± 19 MeV, Γ<sub>t</sub> = 83.6 ± 0.8 MeV. If we do not assume lepton universality, we obtain for the partial decay widths of the Z<sup>0</sup> into e+e−, μ+μ− and τ+ τ−: Γ<sub>e</sub> = 83.3 ± 1.1 MeV, Γ<sub>μ</sub> = 84.5 ± 2.0 MeV, Γ<sub>τ</sub> = 84.0 ± 2.7 MeV. From the measured ratio of the invisible and the leptonic decay widths of the Z<sup>0</sup>, we determine the number of light neutrino species to be Nv =3.05±0.10. We include our measurements of the forward-backward asymmetry for the leptonic channels in a fit to determine the vector and axial-vector neutral current coupling constants of charged leptons to the Z<sup>0</sup>. We obtain g¯<sub>V</sub> = −0.046<sup>+0.015</sup><sub>−0.012</sub> and g¯<sub>A</sub> = −0.500 ± 0.003. In the framework of the Standard Model, we estimate the top quark mass to be m<sub>t</sub> =193<sup>+52</sup><sub>−69</sub> ± 16 (Higgs) GeV, and we derive a value for the weak mixing angle of sin<sup>2</sup>θ<sub>W</sub> ≡ 1 − (M<sub>W</sub>/M<sub>Z</sub>)<sup>2</sup> = 0.222 ± 0.008, corresponding to an effective weak mixing angle of sin<sup>2</sup>θ¯<sub>W</sub> = 0.2315 ± 0.0025.
Facultad de Ciencias Exactas
description We have studied the reactions e+e−→hadrons, e+e−, μ+ μ− and τ+τ−, in the energy range 88.2 ≦ √s ≦ 94.2 GeV. A total luminosity of 5.5 pb<sup>−1</sup>, corresponding to approximately 115000 hadronic and 10000 leptonic Z<sup>0</sup> decays, has been recorded with the L3 detector. From a simultaneous fit to all of our measured cross section data, we obtain assuming lepton universality: M<sub>z</sub> = 91.181 ± 0.010 ± 0.02 (LEP) GeV, Γ<sub>z</sub> = 2501 ± 17 MeV, Γ<sub>had</sub>= 1742 ± 19 MeV, Γ<sub>t</sub> = 83.6 ± 0.8 MeV. If we do not assume lepton universality, we obtain for the partial decay widths of the Z<sup>0</sup> into e+e−, μ+μ− and τ+ τ−: Γ<sub>e</sub> = 83.3 ± 1.1 MeV, Γ<sub>μ</sub> = 84.5 ± 2.0 MeV, Γ<sub>τ</sub> = 84.0 ± 2.7 MeV. From the measured ratio of the invisible and the leptonic decay widths of the Z<sup>0</sup>, we determine the number of light neutrino species to be Nv =3.05±0.10. We include our measurements of the forward-backward asymmetry for the leptonic channels in a fit to determine the vector and axial-vector neutral current coupling constants of charged leptons to the Z<sup>0</sup>. We obtain g¯<sub>V</sub> = −0.046<sup>+0.015</sup><sub>−0.012</sub> and g¯<sub>A</sub> = −0.500 ± 0.003. In the framework of the Standard Model, we estimate the top quark mass to be m<sub>t</sub> =193<sup>+52</sup><sub>−69</sub> ± 16 (Higgs) GeV, and we derive a value for the weak mixing angle of sin<sup>2</sup>θ<sub>W</sub> ≡ 1 − (M<sub>W</sub>/M<sub>Z</sub>)<sup>2</sup> = 0.222 ± 0.008, corresponding to an effective weak mixing angle of sin<sup>2</sup>θ¯<sub>W</sub> = 0.2315 ± 0.0025.
publishDate 1991
dc.date.none.fl_str_mv 1991-06
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/10915/81060
url http://sedici.unlp.edu.ar/handle/10915/81060
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/BF01475788
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
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