Search for time-dependent B-s(0)-(B-s(0))over-bar oscillations using exclusively reconstructed D-s(+/-) mesons

A search for B 0s-B̄ 0s oscillations is performed using a sample of 400 000 hadronic Z 0 decays collected by the SLAG Large Detector experiment. The B 0s candidates are reconstructed in the B 0s→D -sX channel with D -s→Φπ -, K* 0K -. The B 0s production flavor is determined using the large forward-backward asymmetry of polarized Z 0→bb̄ decays and charge information in the hemisphere opposite that of the B 0s candidate. The decay flavor is tagged by the charge of the D ±s. From a sample of 361 candidates with an average B 0s purity of 40%, we exclude the following values of the oscillation frequency: Δm s<1.4 ps -1 and 2.4<Δm s <5.3 ps -1 at the 95% confidence level. © 2002 The American Physical Society.