2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/38340We present a direct measurement of the parity-violation parameter A_c. The measurement is based on 550k Z^0 decays collected by the SLD detector. The mean electron-beam polarization is |P_e| = 73 %. The tagging of c-quark events was performed using two methods: The exclusive reconstruction of D^*+, D^+, and D^0 mesons, and the inclusive P_T spectrum of soft-pions (pi_s) in the decay of D^*+ -> D^0 pi_s^+. The results of these two methods are combined to give A_c = 0.688 +- 0.035(stat.) +- 0.025(sys.) (preliminary).12 pages 4 figures Latex. Contributed to EPS99 and to Lepton-Photon99High Energy Physics - Experimenttext