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.

Hayrapetyan, A., Tumasyan, A., Adam, W., Andrejkovic, J., Bergauer, T., Chatterjee, S., et al. (2024). Measurement of the τ lepton polarization in Z boson decays in proton-proton collisions at = 13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2024(1) [10.1007/JHEP01(2024)101].

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

Xiao J.;Benaglia A.;Boldrini G.;Brivio F.;Cetorelli F.;De Guio F.;Dinardo M. E.;Ghezzi A.;Govoni P.;Guzzi L.;Lucchini M. T.;Malberti M.;Massironi A.;Moroni L.;Paganoni M.;Pinolini B. S.;Ragazzi S.;Tabarelli de Fatis T.;Zuolo D.;Ortona G.;Gerosa R.;
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.
Articolo in rivista - Articolo scientifico
Hadron-Hadron Scattering; Tau Physics;
English
19-gen-2024
2024
2024
1
101
none
Hayrapetyan, A., Tumasyan, A., Adam, W., Andrejkovic, J., Bergauer, T., Chatterjee, S., et al. (2024). Measurement of the τ lepton polarization in Z boson decays in proton-proton collisions at = 13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2024(1) [10.1007/JHEP01(2024)101].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/474519
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