A priori mixing of mesons and the vertical bar Delta I vertical bar=1/2 rule in K ->pi pi

We consider the hypothesis of a priori mixings in the mass eigenstates of m esons to obtain tho \DeltaI\ = 1/2 rule in K --> pi pi. The Hamiltonian res ponsible for the transition is the strong interacting one. The experimental data are described using the isospin symmetry relations between the strong coupling constants.