Troubles with Nonleptonic Charm Decays

Abstract

Conclusions about weak interactions from nonleptonic ${D}^{0}$ decays are completely changed by strong final-state interactions. The suppression of ${D}^{0}\ensuremath{\rightarrow}{\overline{K}}^{0}{\ensuremath{\pi}}^{0}$ found in some models is completely reversed to $\ensuremath{\Gamma}({D}^{0}\ensuremath{\rightarrow}{\overline{K}}^{0}{\ensuremath{\pi}}^{0})=8\ensuremath{\Gamma}({D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+})$ by introduction of experimentally measured $K\ensuremath{\pi}$ scattering phase shifts in the exotic $I=\frac{3}{2}$ and nonexotic $I=\frac{1}{2}$ amplitudes. The $\frac{{K}^{+}{K}^{\ensuremath{-}}}{{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}}$ ratio is very sensitive to meson resonances expected at the $D$ mass. Predictions less sensitive to final-state interactions are discussed.