Author(s): The SLD Collaboration Presenting author: Tracy Usher Corresponding author's e-mail: usher@slac.stanford.edu Title of the presentation: Measurement of A_b and A_c with Leptons from Semileptonic Decay with the SLD Link to the full paper: Session of 1st preference: 5-Test of the Standard Model Session of 2nd preference:   Abstract   The parity violation parameters A_b and A_c of the Z->bbbar and Z->ccbar couplings have been measured directly, using the polar angle dependence of the Z0 pole polarized cross sections. Bottom and charmed hadrons were tagged via semileptonic decays. Both the electron and muon analyses take advantage of new multivariate techniques to increase analyzing power. Based on the 1993-98 SLD sample of 550,000 Z0 decays produced with highly polarized electron beams we measure A_b = 0.919 +/- 0.030_{stat} +/- 0.024_{syst}, A_c = 0.583 +/- 0.055_{stat} +/- 0.055_{syst}.