Study of B-s(0) oscillations and lifetime using fully reconstructed D-s(-) decays

A search for B-s(o) oscillations is performed using approximately 4 million Z --> q (q) over bar events collected by the ALEPH experiment during 1991-1995. B-s(o) candidates are partially reconstructed by combining tracks with fully reconstructed D-s(-) candidates. The B-s(o) production flavour is estimated from the sign of the opposite hemisphere charge, a fragmentation kaon in the same hemisphere, or a lepton in the opposite hemisphere. From a total sample of 1620 candidates, with a B-s(o) purity estimated to be 22%, all values of Delta m(s) below 3.9 ps(-1) and between 6.5 and 8.8 ps(-1) are excluded at 95% CL. From the same sample, the B-s(o) lifetime is measured to be tau(s) = 1.47 +/- 0.14(stat) +/- 0.08(syst) ps. This analysis selects mainly hadronic B-s(o) decays and is statistically independent of a previous ALEPH analysis selecting B-s(o) --> D-s((*)-) rho(+)upsilon candidates. Combining these two analyses yields Delta m(s) > 7.9 ps(-1) at 95% CL and tau(s) = 1.51 +/- 0.11 ps.