Title: Measurement of the Bs Meson Oscillation Frequency with the CDF II Experiment


We report a measurement of the Bs-BsBar oscillation frequency using the CDF II Detector operating at the Fermilab Tevatron collider. This result is derived from 1 fb-1 of p-pbar collisions at a center of mass energy of 1.96 TeV. We use semileptonic and hadronic Bs meson decays and observe a signature consistent with Bs-BsBar oscillations. The probability that background could fluctuate to mimic such a signature is 0.5 %. Under the hypothesis that this is a signal for Bs-BsBar oscillations, we measure Delta m_s = 17.33 +0.42 -0.21 (stat.) +- 0.07 (syst.) ps-1. When combined with the world average value for Delta m_d, this yields|V_td/V_ts| = 0.209 +0.005 -0.008.