12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Measurement of the tau polarization at the Z re...
View graph of relations

« Back

Measurement of the tau polarization at the Z resonance

Research output: Contribution to journalJournal article

Published

Journal publication date1993
JournalZeitschrift für Physik C: Particles and Fields
Journal number3
Volume59
Number of pages18
Pages369-386
Original languageEnglish

Abstract

Using 18.8 pb−1 of data collected in 1990 and 1991, ALEPH has measured the tau polarisation in the decay modes τ→ev vˉ , τ→μv vˉ , τ→πν, τ→ρν and τ→a 1ν, using both the individual tau decay kinematics and the event acollinearity. The measurement of the tau polarisation as a function of the production polar angle yields the two parametersA τ andA e , whereA l =2g v l g A l /(g v l )2+(g A l )2] The resultsA τ=0.143±0.023 andA e =0.120±0.026 are consistent with the hypothesis of electron-tau universality. Assuming universality yields a measurement of the effective weak mixing angle sin2θ w eff=0.2332±0.0022.