Measurement of the Parity-Violation Parameter Ab from the Left-Right Forward-Backward Asymmetry of b Quark Production in Z0 Decays Using a Momentum-Weighted Track-Charge Technique

Using an impact parameter tag to select an enriched sample of Z0→bb¯ events, and the net momentum-weighted track charge to identify the sign of the charge of the underlying b quark, we have measured the left-right forward-backward asymmetry for b quark production as a function of polar angle. Based on 1.8 pb-1 of Z0 decay data produced with a mean electron beam polarization of Pe=63%, this yields a direct measurement of the extent of parity …