Enhancement Mechanism ofD0-Meson Decay

Enhancement of nonleptonic decays of the $D^0$ meson is explained by unitarity sum of quark diagrams with gluon productions, which is expressed by a diagram with nonexotic intermediate states. Experimental values, $\frac{{\Gamma }_{\mathrm{tot}}\left(D^0\right)}{{\Gamma }_{\mathrm{tot}}\left(D^{+}\right)}\approx 10$, are reasonably understood in our model and the enhancement of Cabbibo-suppressed decay of the $D^{+}$ meson is also explained. Our enhancement mechanism leads to the enhancement of $\Delta I=\frac{1}{2}$ amplitudes in nonleptonic decays of $K$ mesons.