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Analysis of the $\tau$ Polarization and its Forward-Backward Asymmetry on the $Z^{0}$
This thesis describes a new a measurement of the tau lepton polarization and its forward-backward asymmetry at the Z resonance using the OPAL detector. This measurement is based on analyses of the tau->electron, muon and pion (Kaon) decays from a sample of 30663 tau-pair events collected in the p...
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Lenguaje: | eng |
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Tel-Aviv University
1996
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Acceso en línea: | http://cds.cern.ch/record/305417 |
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author | Etzion, Erez |
author_facet | Etzion, Erez |
author_sort | Etzion, Erez |
collection | CERN |
description | This thesis describes a new a measurement of the tau lepton polarization and its forward-backward asymmetry at the Z resonance using the OPAL detector. This measurement is based on analyses of the tau->electron, muon and pion (Kaon) decays from a sample of 30663 tau-pair events collected in the polar angle range of Abs(cos(theta)) <0.68 during the 1990-1992 data taking period. Taking then the Standard Model with the V-A structure of the tau lepton decay, we measure the average tau polarization to be <p_tau>=(-13.5+/-2.9+/-2.2)% and the tau polarization forward-backward asymmetry to be AFBpol=(-11.0+/-3.5+/-0.5)% where the first error is statistical and the second systematic. Combining these figures with the OPAL <p_tau> and AFBpol measured with the tau->rho channel we get an average tau polarization, <p_tau>=(-14.9+/-1.9+/-1.3)% and for the asymmetry in the polarization, AFBpol=(-8.9+/-2.2+/-0.9)% . These results are consistent with lepton universality. Combining the two results we obtain for the electroweak mixing angle the value sin^2(theta_W)=0.2331+/-0.0023 within the context of the Standard Model, where the error includes both statistical and systematic uncertainties. |
id | cern-305417 |
institution | Organización Europea para la Investigación Nuclear |
language | eng |
publishDate | 1996 |
publisher | Tel-Aviv University |
record_format | invenio |
spelling | cern-3054172019-09-30T06:29:59Zhttp://cds.cern.ch/record/305417engEtzion, ErezAnalysis of the $\tau$ Polarization and its Forward-Backward Asymmetry on the $Z^{0}$Particle Physics - ExperimentThis thesis describes a new a measurement of the tau lepton polarization and its forward-backward asymmetry at the Z resonance using the OPAL detector. This measurement is based on analyses of the tau->electron, muon and pion (Kaon) decays from a sample of 30663 tau-pair events collected in the polar angle range of Abs(cos(theta)) <0.68 during the 1990-1992 data taking period. Taking then the Standard Model with the V-A structure of the tau lepton decay, we measure the average tau polarization to be <p_tau>=(-13.5+/-2.9+/-2.2)% and the tau polarization forward-backward asymmetry to be AFBpol=(-11.0+/-3.5+/-0.5)% where the first error is statistical and the second systematic. Combining these figures with the OPAL <p_tau> and AFBpol measured with the tau->rho channel we get an average tau polarization, <p_tau>=(-14.9+/-1.9+/-1.3)% and for the asymmetry in the polarization, AFBpol=(-8.9+/-2.2+/-0.9)% . These results are consistent with lepton universality. Combining the two results we obtain for the electroweak mixing angle the value sin^2(theta_W)=0.2331+/-0.0023 within the context of the Standard Model, where the error includes both statistical and systematic uncertainties.Tel-Aviv Universityhep-ex/9606011oai:cds.cern.ch:3054171996 |
spellingShingle | Particle Physics - Experiment Etzion, Erez Analysis of the $\tau$ Polarization and its Forward-Backward Asymmetry on the $Z^{0}$ |
title | Analysis of the $\tau$ Polarization and its Forward-Backward Asymmetry on the $Z^{0}$ |
title_full | Analysis of the $\tau$ Polarization and its Forward-Backward Asymmetry on the $Z^{0}$ |
title_fullStr | Analysis of the $\tau$ Polarization and its Forward-Backward Asymmetry on the $Z^{0}$ |
title_full_unstemmed | Analysis of the $\tau$ Polarization and its Forward-Backward Asymmetry on the $Z^{0}$ |
title_short | Analysis of the $\tau$ Polarization and its Forward-Backward Asymmetry on the $Z^{0}$ |
title_sort | analysis of the $\tau$ polarization and its forward-backward asymmetry on the $z^{0}$ |
topic | Particle Physics - Experiment |
url | http://cds.cern.ch/record/305417 |
work_keys_str_mv | AT etzionerez analysisofthetaupolarizationanditsforwardbackwardasymmetryonthez0 |