POSITIVE PARITY STATES OF 6LI

The energy spectrum of low-lying positive parity states of 6Li provides a good test for the isospin part of the nuclear interaction. The effective nuclear interactions derived by Elliott et al. directly from NN phase shifts and by Shakin et al. from the Yale potential are used here in calculating the 6Li energy spectrum. The projected Hartree-Fock (HF) calculations for the six-nucleon system are done in the model space of the N = 0, 1, 2 and 3 major shells. Since the two lowest axially symmetric K = 1 and K' = 0 HF bands come very close in energy, a band-mixing calculation is carried out. The employed interactions underbind 6Li drastically. If the 3S1 matrix elements are increased by about 35%, the experimental binding energy of 6Li can be reproduced. The effect of this increase is examined on the projected spectrum. As in other 0p shell nuclei, the Elliot interaction gives a good account in view of the fact that the binding energy as well as the low-energy spectrum of 6Li can be fairly well reproduced by increasing the 3S1 matrix elements. © 1969.