A Measurement of the Left-Right Cross Section Asymmetry in Z0 Production with Polarized e+e- Collisions

The Stanford Linear Collider at SLAC is an e+e- collider running at √s ∼ MZ and has provided an electron beam with longitudinal polarization at the SLC interaction point. The 1992 polarized run data were taken with the SLD detector. They present here the measurement of the left-right cross section asymmetry (ALR) for the 1992 run. The polarized run began in May and ended in September of 1992 at a mean center-of-mass energy of 91.56 GeV. Tower hit information of the liquid argon calorimeter and endcap warm iron calorimeter pads were used for selecting hadronic Z0 or tau pair events. The SLD detector collected about 11,000 events during this run. The magnitude of the longitudinal polarization of the electron beam was continuously measured by a polarimeter based on Compton scattering, and was monitored by a polarimeter based on Moller scattering. The luminosity-weighted average longitudinal polarization during the 1992 run was measured as 22.4 ± 0.6(syst.)%