We present the first measurement of the B0(s)-B-bar0_s
oscillation frequency Delta m_s. We use 1 fb-1 of data from p anti-p
collisions at s**(1/2) = 1.96 TeV collected with the CDF II detector at the
Fermilab Tevatron. The sample contains signals of 3,600 fully reconstructed
hadronic B_s decays and 37,000 partially reconstructed semileptonic B_s
decays. We measure the probability as a function of proper decay time that
the B_s decays with the same, or opposite, flavor as the flavor at
production, and we find a signal consistent with B0(s)-B-bar0_s
oscillations. The probability that random fluctuations could produce a
comparable signal is 0.2%. Under the hypothesis that the signal is due to
B0(s)-B-bar0_s oscillations, we measure Delta m_s =
17.31+0.33_-0.18(stat.) +/- 0.07(syst.) ps-1 and determine |V_td/V_ts| =
0.208+0.001_-0.002(exp.)+0.008_-0.006(theo.).
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Updated: Friday, 2006 September 08 13:34:38 CDT automatically from input from Carol Picciolo