DYNAMICAL APPROACH TO THE SELECTION RULE /$delta$I/ =1/2

By giving up the unrenormalizable Lagrangian theory, the problem of weak interactions was studied by means of the unsubtracted dispersion relations. In this formalism the selection rule $|\ensuremath{\Delta}I|=\frac{1}{2}$ in the nonleptonic decays of strange particles is shown to be a consequence of the charge independence of strong interactions. The unsubtracted dispersion relations further serve to determine the coupling constants in strong interactions as eigenvalues. Reasonable agreement with experiment was found for the nonleptonic hyperon decays for the even $\ensuremath{\Sigma}\ensuremath{\Lambda}$ parity.