Effect of Spin-Orbit Interaction on Photonuclear Electric Dipole Absorption

The effect of a nuclear spin-orbit interaction of the form $H_1=\phi \mathrm{}\left(r\right)\mathrm{}\mathrm{l}·\sigma$ on photonuclear electric dipole absorption is examined. We find that the total cross section is unaffected and give expressions for the (small) effect on the average energy of absorption.