PROJECTED HARTREE-FOCK SPECTRA IN P-SHELL

The effective forces derived by Shakin et al. (the S-force) from the NN Yale potential, and by Elliott et al. (the E-force) directly from the NN phase shifts are used in a Hartree-Fock (HF) calculations for 7Li, 8Be, 9Be. The forces are found to underbind these nuclei appreciably. The projected HF spectra for these nuclei are slightly compressed compared to the experimental spectra. In the case of the S-force, the 3 2-, 1 2- levels in 7Li come out almost degenerate, while for the E-force, this splitting is right. If the 3S1 matrix elements of both forces are increased by over 30%, the experimental binding energies for these nuclei can be reproduced. The effect of this increase is to spread out the projected spectra. For the S-force, the spread is too large, and an inversion of the 3 2-, 1 2- levels in 7Li also occurs. For the E-force, the spread is such that it produces better agreement with the experimental levels. Finally, the 3 2-, 1 2- level ordering in 7Li can be reproduced using the S-force if a one-body spin-orbit force is arbitrarily added to the HF Hamiltonian. © 1969.