Analysis of the {Delta}I=1/2 rule and {epsilon}{prime}/{epsilon} with overlap fermions

We study the renormalization of the {Delta}S=1 effective weak Hamiltonian with overlap fermions. The mixing coefficients among dimension-6 operators are computed at one loop in perturbation theory. As a consequence of the chiral symmetry at finite lattice spacing and of the GIM mechanism, which is quadratic in the masses, the K{r_arrow}{pi}{pi} and K{r_arrow}{pi} matrix elements relevant for the {Delta}I=1/2 rule can be computed without any power subtractions. The analogous amplitudes for {epsilon}{prime}/{epsilon} require one divergent subtraction only, which can be performed nonperturbatively using K{r_arrow}0 matrix elements.