Nucleon Self-energy In Nuclear Matter Research Articles

Microscopic calculation of the imaginary part of the nucleon optical potential

We calculate the imaginary part of the nucleon self-energy in nuclear matter, due to the coupling to two-particle, one-hole and one-particle, two-hole excitations. The matrix elements of the full nuclear hamiltonian are evaluated in a correlation operator basis, including two-body and three-body separable terms in the cluster expansion. Our results for scattering states are in agreement with the empirically adjusted optical model parameters at energies below 100 MeV, while at higher energies the calculated points lie somewhat above the empirical ones. For bound states the widths are consistently smaller than the data. A part of this discrepancy we attribute to the coupling to surface vibrations, not present in infinite nuclear matter.