Evidence for D0-D0bar mixing using the CDF II Detector

Understand

We measure the time dependence of the ratio of decay rates for the rare decay D0->K+pi- to the Cabibbo-favored decay D0->K-pi+.

• We use a signal of 12.7 x10^3 D0->K+pi decays with proper decay times between 0.75 and 10 mean D0 lifetimes.
• The data sample was recorded with the CDF II detector at the Fermilab Tevatron and corresponds to an integrated luminosity of 1.5 fb-1 of p-pbar collisions at sqrt(s) = 1.96 TeV.
• We search for D0-D0bar mixing and measure the mixing parameters to be Rd = (3.04 +/- 0.55) x10^{-3}, y' = (8.5 +/- 7.6) x10^{-3}, and x'^2 = (-0.12 +/- 0.35) x10^{-3}.