Behavior of shell-model configuration moments

Abstract

An important input into reaction theory is the density of states or the level density. Spectral distribution theory (also known as nuclear statistical spectroscopy) characterizes the secular behavior of the density of states through moments of the Hamiltonian. One particular approach is to partition the model space into subspaces and find the moments in those subspaces; a convenient choice of subspaces are spherical shell-model configurations. We revisit these configuration moments and find, for complete $0\hslash \omega$ many-body spaces, the following behaviors: (a) the configuration width is nearly constant for all configurations; (b) the configuration asymmetry or third moment is strongly correlated with the configuration centroid; (c) the configuration fourth moment, or excess is linearly related to the square to the configuration asymmetry. Such universal behavior may allow for more efficient modeling of the density of states in a shell-model framework.

12 pages, 8 figures

References in corpus (1)

• Distribution of spectral widths and preponderance of spin-0 ground states in nuclei

Cited by in corpus (8)

• A High-Performance Fortran Code to Calculate Spin- and Parity-Dependent Nuclear Level Densities
• A High-Performance Algorithm to Calculate Spin- and Parity-Dependent Nuclear Level Densities
• Stochastic Estimation of Nuclear Level Density in the Nuclear Shell Model: An Application to Parity-Dependent Level Density in ${}^{58}$Ni
• Benchmarking mean-field approximations to level densities
• Simple models for shell-model configuration densities
• One plus two-body random matrix ensembles with parity: Density of states and parity ratios
• Moments Method for Shell-Model Level Density
• The nuclear density of states and the role of the residual interaction