Search for time-dependent B0s - B0s-bar oscillations using a vertex charge dipole technique

We report a search for B0s - B0s-bar oscillations using a sample of 400,000 hadronic Z0 decays collected by the SLD experiment. The analysis takes advantage of the electron beam polarization as well as information from the hemisphere opposite that of the reconstructed B decay to tag the B production flavor. The excellent resolution provided by the pixel CCD vertex detector is exploited to cleanly reconstruct both B and cascade D decay vertices, and tag the B decay flavor from the charge difference between them. We exclude the following values of the B0s - B0s-bar oscillation frequency: Delta m_s < 4.9 ps-1 and 7.9 < Delta m_s < 10.3 ps-1 at the 95% confidence level.Comment: 18 pages, 3 figures, replaced by version accepted for publication in Phys.Rev.D; results differ slightly from first versio

Search for time-dependent Bs0-Bs0 oscillations using exclusively reconstructed Ds±s mesons

A search for B0s-B0s oscillations is performed using a sample of 400 000 hadronic Z0 decays collected by the SLAC Large Detector experiment. The B0s candidates are reconstructed in the B0s→D-sX channel with D-s→Ππ-, K*0K-. The B0s production flavor is determined using the large forward-backward asymmetry of polarized Z0→bb decays and charge information in the hemisphere opposite that of the B0s candidate. The decay flavor is tagged by the charge of the D±s. From a sample of 361 candidates with an average B0s purity of 40%, we exclude the following values of the oscillation frequency: Δms&lt;1.4 ps-1 and 2.4&lt;Δms &lt;5.3 ps-1 at the 95% confidence level

B(s) mixing at SLD

We set a preliminary 95% C.L. exclusion on the oscillation frequency of $B_s^0 - \bar{B_s^0}$ mixing using a sample of 400,000 hadronic $Z^0$ decays collected by the SLD experiment at the SLC during the 1996-98 run. Three analyses are presented in this paper. The first analysis partially reconstructs the $B_s^0$ by combining a fully reconstructed $D_s$ with the remaining charged B decay tracks. The second analysis selects a sample of events with a partially reconstructed charm vertex and a lepton track. The third analysis reconstructs b-hadrons topologically and exploits the $b \to c$ cascade charge structure to determine the flavor of the b-hadron at decay. All three analyses take advantage of the large forward-backward asymmetry of the polarized $Z^0 \to b \bar{b}$ decays and information in the hemisphere opposite to the reconstructed B vertex to determine the b-hadron flavor at production. The results of the three analyses are combined to exclude the following values of the $B_s^0 - \bar{B_s^0}$ oscillation frequency: $\Delta m_s < 7.6 ps^{-1}$ and $11.8 < \Delta m_s < 14.8 ps^{-1}$ at the 95% confidence level.Comment: 6 pages, 1 figure, contributed to the proceedings of DPF200