Analysis of the Delta I=1/2 rule and epsilon '/epsilon with overlap fermions - art. no. 014506

We study the renormalization of the DeltaS = 1 effective weak Hamiltonian w ith overlap fermions. The mixing coefficients among dimension-6 operators a re computed at one loop in perturbation theory. As a consequence of the chi ral symmetry at finite lattice spacing and of the GIM mechanism, which is q uadratic in the masses, the K-->pi pi and K-->pi matrix elements relevant f or the DeltaI=1/2 rule can be computed without any power subtractions. The analogous amplitudes for epsilon'/epsilon require one divergent subtraction only, which can be performed nonperturbatively using K-->0 matrix elements .