Improved Direct Measurement of Leptonic Coupling Asymmetries with PolarizedZBosons

Koya Abe, Kenji Abe, T. Abe, I. Adam, H. Akimoto, D. Aston, K. G. Baird, C. Baltay, H. R. Band, T. L. Barklow, J. M. Bauer, G. Bellodi (+129 others)
2001 Physical Review Letters  
We present final measurements of the Z boson-lepton coupling asymmetry parameters Ae, Amu, and Atau 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 Ae = 0.1544 +- 0.0060, Amu = 0.142 +- 0.015, and Atau = 0.136 +- 0.015. Combined with our left-right asymmetry measured from hadronic decays, we find Ae = 0.1516 +- 0.0021. Assuming lepton
more » ... ming lepton universality, we obtain a combined effective weak mixing angle of sin**2 theta^{eff}_W = 0.23098 +- 0.00026.
doi:10.1103/physrevlett.86.1162 pmid:11178034 fatcat:pelkey76cveudgywxzd2cpyspm