The first measurement of the left-right cross section asymmetry in Z° boson production [Thesis

Abstract

The first measurement of the left-right cross section asymmetry (A{sub LR}) in Z{sup 0} boson production has been made with the SLAC Large Detector (SLD) at the SLAC Linear Collider (SLC). The measurement was performed at a center-of-mass energy (E{sub cm}) of 91.55 GeV with a longitudinally polarized electron beam. The average beam polarization was (22.4 {+-} 0.6)%. Using a sample of 10,224 Z{sup 0} decays, A{sub LR} is measured to be 0.102 {+-} 0.O44(stat) {+-} 0.003(syst), which determines the effective electroweak mixing angle to be sin{sup 2} {theta}{sub W}{sup eff} = 0.2375 {+-} 0.0056(stat) {+-} 0.0004(syst).