Electromagnetic corrections to K ->pi pi. II. Dispersive matching - art. no. 093002

We express the leading electromagnetic corrections in K --> pi pi as integr als over the virtual photon squared momentum Q(2). The high Q(2) behavior i s obtained via the operator product expansion. The low Q(2) behavior is cal culated using chiral perturbation theory. We model the intermediate Q(2) re gion using resonance contributions in order to enforce the matching of thes e two regimes. Our results confirm our previous estimates that the electrom agnetic corrections provide a reasonably small shift in the Delta I = 3/2 a mplitude.