Measurement of the asymmetry of b quark production in e+e- annihilation at {Mathematical expression}

The forward-backward asymmetry in the reaction e+e-→bb has been determined at centre of mass energies near 35 GeV using the TASSO detector. We report results from three different methods. The combined result of the measurements is {Mathematical expression} ignoring {Mathematical expression} mixing. Taking mixing into account leads to a corrected asymmetry of {Mathematical expression}. The axial vector coupling constant of the b quark as calculated from the corrected asymmetry is ab=-1.2±0.5 to be compared with the value abSM=-1 from the standard model. © 1990 Springer-Verlag.