Direct measurement of leptonic coupling asymmetries with polarized Z bosons

Abstract

We present direct measurements of the Z0–lepton coupling asymmetry parameters Ae, Aμ, and Aτ, based on a data sample of 12 063 leptonic Z0 decays collected by the SLD detector. The Z bosons are produced in collisions of beams of polarized e- with unpolarized e+ at the SLAC Linear Collider. The couplings are extracted from the measurement of the left-right and forward-backward asymmetries for each lepton species. The results are Ae=0.152±0.012(stat)±0.001(syst), Aμ=0.102±0.034±0.002, and Aτ=0.195±0.034±0.003. © 1997 The American Physical Society.