Bs Mixing at the Tevatron

The measurement of the Bs mixing oscillation frequency, Δms, has been the main goal for both experiments CDF and D0 which are running at the Tevatron collider. With 1 fb-1of data collected during the last four years D0 set a lower and upper limit on this frequency, . CDF measured Δms with a precision better than 2% and the probability that the data could randomly fluctuate to mimic such a signature is 0.2%