Electromagnetic Corrections to the One-Pion-Exchange Potential

Leading-order electromagnetic loop corrections to the one-pion-exchange potential are computed within the framework of chiral perturbation theory. These corrections generate an effective nucleon-nucleon potential, V{sub {pi}{gamma}} , which supplements the sum of one-pion-exchange potential and the nucleon-nucleon Coulomb potential. This potential is charge dependent and its construction is demonstrated to be gauge invariant. The potential V{sub {pi}{gamma}} has been included in the Nijmegen partial-wave analysis of np data. A particular renormalization scheme is chosen that leads to a negligible change in the {pi}{sup {plus_minus}}NN coupling constant and in the np {sup 1}S{sub 0} scattering length and effective range. {copyright} {ital 1998} {ital The American Physical Society}