Time-dependent Bs0–B̄s0 mixing using inclusive and semileptonic B decays at SLD

We have searched for time-dependent Bs0–B̄s0 mixing using a sample of 400 000 hadronic Z0 decays collected by the SLD experiment at the SLC. The analyses take advantage of the excellent vertexing efficiency and resolution of the pixel-based CCD Vertex Detector which provides a B decay length resolution of approximately 100 μm. All analyses determine the B hadron flavor at production by exploiting the large forward–backward asymmetry of polarized Z0→bb̄ decays. This flavor tag is enhanced by incorporating additional information from the hemisphere opposite that of the reconstructed B decay. In one analysis, B decay vertices are reconstructed inclusively with a topological technique, and separation between Bs0 and B̄s0 decays is based on the reconstruction of a “charge dipole” of the topological vertices to exploit the Bs0→Ds− cascade charge structure. The other two analyses select semileptonic decays to tag the B flavor at decay and reconstruct the B decay vertex by intersecting the lepton with either all tracks in the nearest jet or the trajectory of a topologically reconstructed D vertex. The three analyses are combined to exclude the following values of the oscillation frequency: Δms<5.3 and 6.0 ps−1<Δms<11.5 ps−1. Future prospects are outlined.