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

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.