We obtain the relativistic distorted wave impulse approximation amplitude for nucleon-nucleus collective transitions using an eikonal formalism. The effect of the Darwin term is to suppress the upper-to-upper contribution and enhance the lower-to-lower compared with a nonrelativistic treatment. In collective transitions these combine in a way that results in a transition density proportional to the derivative of the total Dirac distortion including quadratic and spin-orbit pieces. This leads to the same phenomenologically successful relations between elastic and inelastic amplitudes as in the Schrödinger description for collective transitions and promises a better treatment of non-collective transitions. We comment on the vanishing of $P-A$ in this treatment.

• Received 22 July 1983

DOI:https://doi.org/10.1103/PhysRevC.28.2392