The use of off-shell potentials in Brueckner theory calculations of the nucleon optical potential

Abstract

We calculate the nucleon optical potential from the Hamada-Johnston potential using first-order Brueckner theory. The new feature is that we use a fully complex off-shell potential in the energy denominator in the calculation of the -matrix in place of the usually used real part of the on-shell potential. We find that for bombarding energies near 30 MeV the agreement with experimental data is satisfactory while at higher energies the general results from the on- and off-shell potentials are very similar. The reason for the better agreement at the lower energies using the off-shell potential in the energy denominator is that the calculated optical potential in this case has a much smaller imaginary part.