Solution to the puzzle of Γ(D0→K+K-)/Γ(D0→π+π-) in a unified approach to D→πK-bar,KK-bar, and ππ and K→ππ decays

A nonperturbative algebraic approach, which deals with long-distance physics in earnest but also maintains a close contact with quark-line diagrams, has previously been applied to the derivation of the chemical bondΔIchemical bond = (1/2 rule in the K→2π decays. Reasonable estimates of the rates of D0→πK-bar and phiK-bar0 decays in terms of the rate of K/sub S/0→ππ decay have also been obtained, to the approximation in which excited state contributions to the on-mass-shell intermediate states are being neglected for the moment. In this paper, we examine our unified approach to the D→πK-bar, KK-bar, and ππ and K→ππ decays further, now including the four-quark [QQ][Q-barQ-bar] meson contribution to the on-mass-shell intermediate states. We find that the result provides us with a solution to the well-known puzzle in the observed rates of various Cabibbo-suppressed decays of the D0 meson, particularly Γ(D0→K+K-)/Γ(D0→π+π-)≅3.6, which has never been solved in a systematic manner. In addition, it gives us a significantly improved prediction on Γ(D0→πK-bar) in comparison with Γ(K/sub S/0→ππ)