Results on D0 - antiD0

We present results on D0 mixing from Fermilab experiment E691, using events of the type D*+ → π+D0, with D0 → K+π- and D0 → K+π-π+π-. The charge of the bachelor pion tags the charm quantum number of the D0 meson at production. The decay time is used to separate mixing from doubly Cabibbo-suppressed decays. We observe no evidence for mixing in either mode. Combining the results from the two decay modes, we find τM = 0.0005±.0020 or τM < .0037 at the 90% confidence level, where τM is the ratio of wrong sign decays from mixing to right sign decays. We also present limits on doubly Cabibbo suppressed decays