2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/181644A recently proposed strategy to quantify the role of the charm quark mass in the $ΔI=1/2$ rule is reviewed. Results for the low-energy couplings of the $ΔS=1$ chiral effective Hamiltonian in a theory with a light charm quark (GIM limit) are obtained through a matching of three-point correlation functions computed in Chiral Perturbation Theory and in quenched lattice QCD. We observe a large $ΔI=1/2$ enhancement, which is not large enough to explain the experimental result, but suggests significant long-distance contributions to the physical $ΔI=1/2$ which are unrelated to penguin contractions or operators.16 pages, 8 figures, Plenary talk at Lattice 2006, to appear in Proceedings of Science PoS(LAT2006)012High Energy Physics - Latticetext