Bd0-Bd0 mixing measurements at SLD

The time dependence of Bd0-Bd0 mixing has been measured using a sample of 150 000 hadronic Z0 decays collected by the SLD experiment at the SLC between 1993 and 1995. Four different analyses have been performed. All analyses tag the B candidate at production with a combined tag that exploits the large polarized b forward-backward asymmetry together with the opposite hemisphere b jet charge. Two of the analyses exploit 3D topological vertexing to determine the B meson decay length, in conjunction with either a charged kaon or charge dipole final state tag. The other two analyses use identified high (p,pt) leptons intersected with either a partially reconstructed D meson, or the weighted average of tracks in the b jet. Taking into account correlated statistical and systematic errors, the preliminary SLD average for the mass difference between the two Bd0 mass eigenstates is: Δmd 0.525±0.043(stat)±0.037(syst) ps-1. (orig.)