Nonleptonic decays of charm mesons

We investigate the possibility that both nonleptonic strange-particle and charm-particle decays can be understood in terms of one effective nonleptonic Hamiltonian $H_{\mathrm{eff}}=H_0+H_{\mathrm{COR}}$. $H_0$ is a usual four-fermion current-current interaction term and the $H_{\mathrm{COR}}$ is the color-radius interaction term. The color-radius interaction is known to explain the $\Delta I=\frac{1}{2}$ rule in strange-particle decays. The effects of $H_{\mathrm{COR}}$ as well as those of final-state interaction on two-body charm-meson decays are examined. The theory is in qualitative agreement with all measured branching ratios. Predictions for charm-meson decays into two pseudoscalar mesons are presented.