Shell-model studies of statistical approximations to model interactions

C. R. Countee, Louisiana State University
J. P. Draayer, Louisiana State University
T. R. Halemane, University of Rochester
K. Kar, University of Rochester


Statistical nuclear spectroscopy points to the importance of traces of bilinear products of operators acting in a model space. This leads to an algorithm for expanding any interaction in terms of simpler operators, which takes on special significance when the space is first partitioned by symmetries and the approximation is required to reproduce subspace centroids. Here, in anticipation of applications in statistical spectroscopy where the use of trace-equivalent forms for operators can lead to major simplifications, we report on detailed shell-model comparisons of excitation spectra, eigenstate overlaps and B(E2) transition strengths in 20Ne and 22Ne with a realistic interaction and its configuration-isospin and SU(3) trace-equivalent approximations. SU(3) symmetry breaking by single-particle shell effects is studied and renormalization procedures for trace-equivalent approximations are investigated. © 1981.