The lorentz structure of the imaginary optical potential

Abstract

The relativistic imaginary optical potential is calculated to lowest order in nuclear matter for the exchange of σ-, ω- and π-mesons. Analytic results are obtained which show that: (i) the imaginary scalar potential is positive (a probability source); (ii) both it and the imaginary vector potential are large (about five times the nonrelativistic net absorption); (iii) there is an important imaginary spatial three-vector potential. These results can explain, the sign, magnitude and energy dependence of the imaginary spin-orbit optical potential. For pions, orders of magnitude larger potentials are obtained for pseudoscalar rather than pseudovector πN coupling. The pseudovector results represent moderate corrections to σ- and ω-exchange.