A measurement of the B^0-anti-B^0 oscillation frequency and   determination of flavor-tagging efficiency using semileptonic and hadronic   B^0 decays
  B^0-anti-B^0 flavor oscillations are studied in e^+e^- annihilation data collected with the BABAR detector at center-of-mass energies near the Y(4S) resonance. One B is reconstructed in a hadronic or semileptonic decay mode, and the flavor of the other B in the event is determined with a tagging algorithm that exploits the relation between the flavor of the heavy quark and the charges of its decay products. Tagging performance is characterized by an efficiency e_i and a probability for mis-identification, w_i, for each tagging category. We report a determination of the wrong-tag probabilities, w_i, and a preliminary result for the time-dependent B^0-anti-B^0 oscillation frequency, Delta_md = 0.512+/-0.017+/-0.022 hbar-ps^{-1}. 
The BABAR Collaboration, B. Aubert, et al