? -? scattering, QED, and finite-volume quantization

Using the Coulomb gauge formulation of QED, we present a lattice QCD procedure to calculate the ???????? scattering phase shift including the effects of the Coulomb potential, which appears in this formulation. The approach described here incorporates the effects of relativity and avoids finite-volume corrections that vanish as a power of the volume in which the lattice calculation is performed. This is the first step in developing a complete lattice QCD calculation of the electromagnetic and isospin-breaking light-quark mass contributions to ??0, the parameter describing direct CP violating effects in KL ??? ???? decay.