Statistical Properties of 56-57Fe with Multi-Shell Degrees of Freedom

TL;DR

This paper models the statistical properties of 56-57Fe using a comprehensive shell model that includes pairing, spin, and continuum effects, successfully matching experimental data across temperature regimes.

Contribution

It introduces a multi-shell, all-nucleon model with continuum states for accurate statistical property predictions of medium-heavy nuclei.

Findings

Accurate excitation energy, heat capacity, and level density predictions.

Model aligns well with experimental data across temperature ranges.

Inclusion of continuum states extends model validity to high temperatures.

Abstract

We investigate the statistical properties of 56-57Fe within a model capable of treating all the nucleons as active in an infinite model space including pairing effects. Working within the canonical ensemble, our model is built on single-particle states, thus it includes shell and subshell closures. We include spin correlation parameters to account for nucleon spin multiplicities. Pairing and shell effects are important in the low-temperature region where the quantum effects dominate. The validity of the model is extended to higher temperatures, approaching the classical regime, by including continuum states. We present results for excitation energy, heat capacity and level density of 56-57Fe. The resulting favorable comparisons with experimental data and with other approaches, where applicable, indicate that the methods we develop are useful for statistical properties of medium to heavy nuclei.