A comprehensive summary of recent progress in the understanding of nonleptonic weak decays of strange particles is presented. The dynamics of these processes is strongly influenced by nonperturbative correlations between two quarks in scalar color-antitriplet states. A coherent description of the $\Delta I=\frac{1}{2}$ rule in kaon and hyperon decays as well as the $K_L-K_S$ mass difference emerges, resolving so far mysterious puzzles. In all cases, the calculations are free of undetermined parameters. Extensive use is made of chiral symmetry and chiral perturbation theory. Relations of our ideas to other approaches, namely, the $\frac{1}{N_c}$ expansion, dual QCD sum rules, and lattice gauge theory, are pointed out.

• Received 13 February 1991

DOI:https://doi.org/10.1103/PhysRevD.44.775