Statistical Properties of Nuclei: Beyond the Mean-Field Approximation
Paul Fanto, Yale University
Statistical properties of nuclei, in particular nuclear level densities, are important inputs to the Hauser-Feshbach model of compound-nucleus reactions. This statistical reaction model has important applications in basic nuclear science, nuclear astrophysics, and stockpile stewardship. Phenomenological models of level densities become unreliable when extrapolated to rare isotopes and mean-field methods based on an effective nuclear interaction neglect important correlation effects. In this talk, I will present an application of the static-path plus random-phase approximation (SPA+RPA) to calculate the state densities of heavy nuclei. The SPA+RPA includes large-amplitude static fluctuations and small-amplitude quantal fluctuations beyond the mean-field approximation. We show that the SPA+RPA provides an excellent description of the state densities of samarium isotopes. In particular, the SPA+RPA naturally reproduces the collective enhancement relative to mean-field state densities in deformed nuclei.
Abstract Author(s): Paul Fanto