Quark dynamics and the weak non-leptonic decays of K and D mesons

Quark model predictions for K → 2π and D → Kπ decays were investigated in dynamical frameworks based on the separable approximation (SA), current algebra (CA), current algebra modified for the meson moment dependence (CAC) and current algebra with final-state interactions (CAF). Relativistic and non-relativistic quark model predictions were compared. The effective weak hamiltonian was modified by changing the relative strengths of its flavour $\text{20}\text{and}\text{84}$ parts. All these approaches were also applied to hyperon and $\text{Ω}{}^{\mathrm{?}}$ non-leptonic decays. When using standard QCD enhancement, the best approximation for K → 2π (CAC) works poorly with D → Kπ. The best approximatiob for D→Kπ (CAF) fails in the case of K → 2π. Only CAC with the $\text{84}$ piece of the hamiltonian quenched might be in agreement with studied weak decays.