The polarization of τ leptons is measured using leptonic and hadronic τ lepton decays in Z → τ+ τ− events in proton-proton collisions at (Formula presented.) 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 effective weak mixing angle sin2 θWeff , independently of the Z boson production mechanism. The obtained value sin2 θWeff = 0.2319 ± 0.0008(stat) ± 0.0018(syst) = 0.2319 ± 0.0019 is in good agreement with measurements at e+ e− colliders.

Null, N., Hayrapetyan, A., Tumasyan, A., Adam, W., Andrejkovic, J.W., Bergauer, T., et al. (2024). Measurement of the τ lepton polarization in Z boson decays in proton-proton collisions at √s = 13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2024(1), 0-53 [10.1007/jhep01(2024)101].

Measurement of the τ lepton polarization in Z boson decays in proton-proton collisions at √s = 13 TeV

Battilana, C.;Bonacorsi, D.;Borgonovi, L.;Cuffiani, M.;Diotalevi, T.;Fanfani, A.;Giommi, L.;Guiducci, L.;Rovelli, T.;Siroli, G. P.;
2024

Abstract

The polarization of τ leptons is measured using leptonic and hadronic τ lepton decays in Z → τ+ τ− events in proton-proton collisions at (Formula presented.) 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 effective weak mixing angle sin2 θWeff , independently of the Z boson production mechanism. The obtained value sin2 θWeff = 0.2319 ± 0.0008(stat) ± 0.0018(syst) = 0.2319 ± 0.0019 is in good agreement with measurements at e+ e− colliders.
2024
Null, N., Hayrapetyan, A., Tumasyan, A., Adam, W., Andrejkovic, J.W., Bergauer, T., et al. (2024). Measurement of the τ lepton polarization in Z boson decays in proton-proton collisions at √s = 13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2024(1), 0-53 [10.1007/jhep01(2024)101].
Null, Null; Hayrapetyan, A.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.; Escalante Del Va...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1003154
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