Direct measurement of parity violation in the coupling of Z(0) bosons to b quarks using a mass tag and momentum-weighted track charge

We present a direct measurement of the parity-violation parameter A{sub b} using a self-calibrating track-charge technique. In the SLAC Linear Collider Large Detector (SLD) experiment we observe hadronic decays of Z{sup 0} bosons produced in collisions between longitudinally polarized electrons and unpolarized positrons at the SLAC Linear Collider. A sample of b{bar b} events is selected using the topologically reconstructed mass of B hadrons. From our 1993{endash}1995 sample of approximately 150000 hadronic Z{sup 0} decays, we obtain A{sub b}=0.911{plus_minus}0.045(stat) {plus_minus}0.045(syst) . {copyright} {ital 1998} {ital The American Physical Society}