MULTICONFIGURATION RESONATING-GROUP THEORY OF LI-8

The nucleus Li8 is studied with a multiconfiguration resonating-group calculation which consists of n+7Li, t+5He, n+7Li*, and 4H+ cluster configurations. With no adjustable parameters, the results show that the calculated level spectrum agrees well with experiment and with the empirical level spectrum obtained by Knox, Resler, and Lane using an extensive R-matrix analysis. A calculation employing only the n+7Li configuration is found to be generally inadequate. Among the configurations t+5He, n+7Li*, and 4H+ which are employed to enlarge the model space, the n+7Li* configuration is shown to be the most important from an overall viewpoint. Comparisons between calculated and experimental scattering and reaction cross sections have also been made. Here one finds that the calculation explains all the main features of measured results. In particular, the triton production cross section of the Li7(n,nt) reaction is well reproduced. The calculated n+7Li total reaction cross section turns out to be somewhat too small, being equal to around 75% of the experimental value. © 1990 The American Physical Society.