Unusual decay modes ofD0andD+mesons

CLEO has measured decay modes of the $D^0$ and $D^{+}$ into final states consisting of $K^{\pm }\text{'}\mathrm{s}$, ${\pi }^{\pm }\text{'}\mathrm{s}$, $K^0\text{'}\mathrm{s}$ and ${\overline{K}}^0\text{'}\mathrm{s}$, using data taken with the CLEO detector at the Cornell Electron Storage Ring. We report new results on the decays of $D^0\text{'}\mathrm{s}$ into $4{\pi }^{\pm }$, $K^{-}{K}^{+}{\pi }^{-}{\pi }^{+}$, ${\overline{K}}^0{K}^{+}{K}^{-}$, ${\overline{K}}^0{K}^{+}{\pi }^{-}$, $K^0{K}^{-}{\pi }^{+}$, $3K_S^0$ and ${\overline{K}}^0\phi$ together with some of their resonant substructure. We also present the first observation of the decay $D^{+}\to {\overline{K}}^0{\overline{K}}^0{K}^{+}$ and give limits on the doubly-Cabibbo-suppressed decays of the $D^0$ into $K^{+}{\pi }^{-}$ and $K^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$.