Hayrapetyan, A.Tumasyan, A.Adam, W.Andrejkovic, J.W.Bergauer, T.Chatterjee, S.Sağır, SinanCMS Collaboration2024-05-102024-05-102024The CMS collaboration., Hayrapetyan, A., Tumasyan, A. et al.(2024). Measurement of the τ lepton polarization in Z boson decays in proton-proton collisions at (Formula presented.). Journal of High Energy Physics. 2024, 1.https://doi.org/10.1007/JHEP01(2024)1011029-8479https://doi.org/10.1007/JHEP01(2024)101https://hdl.handle.net/11492/8445WOS:001190239900001The 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. [Figure not available: see fulltext.].enHadron-Hadron ScatteringTau PhysicsArticle20241info:eu-repo/semantics/openAccess2-s2.0-85185595948WOS:00119023990000110.1007/JHEP01(2024)101Q1N/A