Cabibbo-suppressed nonleptonicDdecays

Abstract

We discuss why an extension of the ideas used to explain the $\Delta I=\frac{1}{2}$ rule in kaon and hyperon decays does not lead to an analogous large enhancement in the rates of Cabibbo-suppressed nonleptonic $D$-meson decays. The possibility of seeing the contribution of diagrams with a virtual $b$-quark loop through interference effects is also discussed.