Measurement of the τ lepton polarization in Z boson decays in proton-proton collisions at √s = 13 TeV
The polarization of τ leptons is measured using leptonic and hadronic τ lepton decays in Z → τ + τ − events in proton-proton collisions at √s = 13 TeV recorded by CMS at the CERN LHC with an integrated luminosity of 36.3 fb−¹ . The measured τ − lepton polarization at the Z boson mass pole is Pτ (Z)...
| Autores: | , , , , , , , , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad de Cantabria (UC) |
| Repositorio: | UCrea Repositorio Abierto de la Universidad de Cantabria |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unican.es:10902/33983 |
| Acceso en línea: | https://hdl.handle.net/10902/33983 |
| Access Level: | acceso abierto |
| Palabra clave: | Hadron-Hadron Scattering Tau Physics |
| Sumario: | The polarization of τ leptons is measured using leptonic and hadronic τ lepton decays in Z → τ + τ − events in proton-proton collisions at √s = 13 TeV recorded by CMS at the CERN LHC with an integrated luminosity of 36.3 fb−¹ . The measured τ − lepton polarization at the Z boson mass pole is Pτ (Z) = −0.144 ± 0.006 (stat) ± 0.014 (syst) = −0.144 ± 0.015, in good agreement with the measurement of the τ lepton asymmetry parameter of Aτ = 0.1439 ± 0.0043 = −Pτ (Z) at LEP. The τ lepton polarization depends on the ratio of the vector to axial-vector couplings of the τ leptons in the neutral current expression, and thus on the efective weak mixing angle sin²θef W, independently of the Z boson production mechanism. The obtained value sin²θ eff W = 0.2319 ± 0.0008(stat) ± 0.0018(syst) = 0.2319 ± 0.0019 is in good agreement with measurements at e+e− colliders. |
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