An Improved Direct Measurement of Leptonic Coupling Asymmetries with Polarized Z bosons

Abstract

We present final measurements of the Z boson-lepton coupling asymmetry parameters A{sub e}, A{sub {mu}}, and A{sub {tau}} with the complete sample of polarized Z bosons collected by the SLD detector at the SLAC Linear Collider. From the left-right production and decay polar angle asymmetries in leptonic Z decays we measure A{sub e} = 0.1544 {+-} 0.0060, A{sub {mu}} = 0.142 {+-} 0.015, and A{sub {tau}} = 0.136 {+-} 0.015. Combined with our left-right asymmetry measured from hadronic decays, we find A{sub e} = 0.1516 {+-} 0.0021. Assuming lepton universality, we obtain a combined effective weak mixing angle of sin{sup 2} {theta}{sub W}{sup eff} = 0.23098 {+-} 0.00026.