High-Performance Algorithm for Calculating Non-Spurious Spin- and Parity-Dependent Nuclear Level Densities

TL;DR

This paper introduces an advanced high-performance algorithm that accurately calculates spin- and parity-dependent nuclear level densities, effectively eliminating spurious states and improving agreement with exact models and experimental data.

Contribution

It presents a new algorithm based on the statistical moments method that removes spurious center-of-mass excitations in shell model calculations for multi-shell nuclei.

Findings

The algorithm successfully eliminates spurious states in sd-shell nuclei.

Results closely match exact shell model calculations.

The method improves the accuracy of nuclear level density predictions.

Abstract

A new high-performance algorithm for calculating the spin- and parity-dependent shell model nuclear level densities using methods of statistical spectroscopy in the proton-neutron formalism was recently proposed. When used in valence spaces that cover more than one major harmonic oscillator shell, this algorithm mixes the genuine intrinsic states with spurious center-of-mass excitations. In this paper we present an advanced algorithm, based on the recently proposed statistical moments method, that eliminates the spurious states. Results for unnatural parity states of several sd-shell nuclei are presented and compared with those of exact shell model calculations and experimental data.