A MEASUREMENT OF tau-POLARIZATION AT LEP

Journal article

With a data sample of 86 000 Z → τ+τ-(γ) events collected in 1990 through 1993 we have measured the polarization of τ-leptons as a function of the production polar angle using the following 1-prong τ decay modes: τ-→e-vevτ, τ-→π- (K-)vτ, τ-→ρ{variant}-vτ and τ-→a1-vτ. We obtain for the ratio vector to axial-vector weak neutral couplings for electrons gVe/gAe=0.0791±0.0099(stat)±0.0025 (syst) and taus gVτ/gAτ=0.0752±0.0063 (stat)±0.0045 (syst) consistent with the hypothesis of e - τ universality. Assuming universality of the e - τ neutral current we determine the effective electroweak mixing angle to be sin2 θeffw = 0.2309 ± 0.0016. © 1994.

Authors: Acciarri, M; Adams, A; Adriani, O; Aguilarbenitez, M; Ahlen, S

• Publication status: Published
• Journal: Physics Letters B
• Volume: 341
• Issue: 2
• Pages: 245-256
• Publication date: 1994-12-29
• DOI: 10.1016/0370-2693(94)90316-6
• ISSN: 0370-2693