EXPERIMENTAL PROBES OF FINAL-STATE INTERACTIONS IN D0-MESON DECAYS

Using data from the Fermilab photoproduction experiment E691, we have measured the branching ratio for the decay D0-->K0-pi-0BAR to be (5.0+/-0.8+/-0.9)%. We see no evidence for the decay D0-->K0K0BAR and set a 90% confidence level upper limit of 0.12%. The large K0-pi-0BAR branching ratio (relative to K-pi+) indicates either a lack of color suppression or significant elastic final-state interactions. The upper limit on the K0K0BAR mode indicates that final-state interactions mix final states such as K+K- or pi+pi- into the K0K0BAR less than 27% of the time at the 90% confidence level.