Title: Precise measurement of the left-right cross section asymmetry in Z boson production by e+e− collisions
Abstract: We present a precise measurement of the left-right cross section asymmetry (ALR) for Z boson production by e+e− collisions. The measurement was performed at a center-of-mass energy of 91.26 GeV with the SLD detector at the SLAC Linear Collider (SLC). The luminosity-weighted average polarization of the SLC electron beam was (63.0±1.1)%. Using a sample of 49,392 Z decays, we measure ALR to be 0.1628±0.0071(stat.)±0.0028(syst.) which determines the effective weak mixing angle to be sin2 θWfeff = 0.2292 ± 0.0009(stat.) ± 0.0004(syst.).