A precise measurement of the tau polarisation at LEP-1
The τ polarisation has been studied with the e+e- → τ+τ- data collected by the DELPHI detector at LEP in 1993, 1994 and 1995 around the Z resonance firstly through the exclusive decay channels evv̄, μvvμ, πv, ρv, and a1v and secondly with an inclusive hadronic analysis which benefits from a higher e...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2000
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| _version_ | 1826260765543235584 |
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| author | Abreu, P Adam, W Adye, T Adzic, P Ajinenko, I Albrecht, Z Alderweireld, T Alekseev, G Alemany, R Allmendinger, T Allport, P Almehed, S Amaldi, U Amapane, N Amato, S Anassontzis, E Andersson, P Andreazza, A Andringa, S Antilogus, P Apel, W Arnoud, Y Asman, B Augustin, J Augustinus, A |
| author_facet | Abreu, P Adam, W Adye, T Adzic, P Ajinenko, I Albrecht, Z Alderweireld, T Alekseev, G Alemany, R Allmendinger, T Allport, P Almehed, S Amaldi, U Amapane, N Amato, S Anassontzis, E Andersson, P Andreazza, A Andringa, S Antilogus, P Apel, W Arnoud, Y Asman, B Augustin, J Augustinus, A |
| author_sort | Abreu, P |
| collection | OXFORD |
| description | The τ polarisation has been studied with the e+e- → τ+τ- data collected by the DELPHI detector at LEP in 1993, 1994 and 1995 around the Z resonance firstly through the exclusive decay channels evv̄, μvvμ, πv, ρv, and a1v and secondly with an inclusive hadronic analysis which benefits from a higher efficiency and a better systematic precision. The results have been combined with those previously published on 1990 to 1992 DELPHI data, to produce results which reflect the full LEP-1 statistics. The fit of the τ polarisation dependence on the production angle yielded the polarisation parameters Aτ = 0.1359 ± 0.0096 and Ae = 0.1382 ± 0.0116. From these results the ratio of the vector and axial-vector effective couplings v̄τ/āτ = 0.0683 ± 0.0048 and v̄e/āe = 0.0694 ± 0.0058 have been derived, compatible with e-τ universality. With the assumption of lepton universality, the ratio of vector to axial-vector effective couplings for leptons v̄ι/āι = 0.0687 ± 0.0037 was obtained, implying a value of the effective weak mixing angle sin2 θlepteff= 0.23282 ± 0.00092. |
| first_indexed | 2024-03-06T19:10:53Z |
| format | Journal article |
| id | oxford-uuid:16bb84aa-9b6c-41df-a096-40ec2db449a1 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:10:53Z |
| publishDate | 2000 |
| record_format | dspace |
| spelling | oxford-uuid:16bb84aa-9b6c-41df-a096-40ec2db449a12022-03-26T10:33:05ZA precise measurement of the tau polarisation at LEP-1Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:16bb84aa-9b6c-41df-a096-40ec2db449a1EnglishSymplectic Elements at Oxford2000Abreu, PAdam, WAdye, TAdzic, PAjinenko, IAlbrecht, ZAlderweireld, TAlekseev, GAlemany, RAllmendinger, TAllport, PAlmehed, SAmaldi, UAmapane, NAmato, SAnassontzis, EAndersson, PAndreazza, AAndringa, SAntilogus, PApel, WArnoud, YAsman, BAugustin, JAugustinus, AThe τ polarisation has been studied with the e+e- → τ+τ- data collected by the DELPHI detector at LEP in 1993, 1994 and 1995 around the Z resonance firstly through the exclusive decay channels evv̄, μvvμ, πv, ρv, and a1v and secondly with an inclusive hadronic analysis which benefits from a higher efficiency and a better systematic precision. The results have been combined with those previously published on 1990 to 1992 DELPHI data, to produce results which reflect the full LEP-1 statistics. The fit of the τ polarisation dependence on the production angle yielded the polarisation parameters Aτ = 0.1359 ± 0.0096 and Ae = 0.1382 ± 0.0116. From these results the ratio of the vector and axial-vector effective couplings v̄τ/āτ = 0.0683 ± 0.0048 and v̄e/āe = 0.0694 ± 0.0058 have been derived, compatible with e-τ universality. With the assumption of lepton universality, the ratio of vector to axial-vector effective couplings for leptons v̄ι/āι = 0.0687 ± 0.0037 was obtained, implying a value of the effective weak mixing angle sin2 θlepteff= 0.23282 ± 0.00092. |
| spellingShingle | Abreu, P Adam, W Adye, T Adzic, P Ajinenko, I Albrecht, Z Alderweireld, T Alekseev, G Alemany, R Allmendinger, T Allport, P Almehed, S Amaldi, U Amapane, N Amato, S Anassontzis, E Andersson, P Andreazza, A Andringa, S Antilogus, P Apel, W Arnoud, Y Asman, B Augustin, J Augustinus, A A precise measurement of the tau polarisation at LEP-1 |
| title | A precise measurement of the tau polarisation at LEP-1 |
| title_full | A precise measurement of the tau polarisation at LEP-1 |
| title_fullStr | A precise measurement of the tau polarisation at LEP-1 |
| title_full_unstemmed | A precise measurement of the tau polarisation at LEP-1 |
| title_short | A precise measurement of the tau polarisation at LEP-1 |
| title_sort | precise measurement of the tau polarisation at lep 1 |
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