Level densities of nickel isotopes: microscopic theory versus experiment

Abstract

We apply a spin-projection method to calculate microscopically the level densities of a family of nickel isotopes ${}^{59-64}$Ni using the shell model Monte Carlo approach in the complete $pf{g}_{9/2}$ shell. Accurate ground-state energies of the odd-mass nickel isotopes, required for the determination of excitation energies, are determined using the Green's function method recently introduced to circumvent the odd particle-number sign problem. Our results are in excellent agreement with recent measurements based on proton evaporation spectra and with level counting data at low excitation energies. We also compare our results with neutron resonance data, assuming equilibration of parity and a spin-cutoff model for the spin distribution at the neutron binding energy, and find good agreement with the exception of ${}^{63}$Ni.

5 pages, 3 figures, 2 tables, submitted to Phys. Rev. C, Rapid Communications

References in corpus (4)

• Spin projection in the shell model Monte Carlo method and the spin distribution of nuclear level densities
• Heavy deformed nuclei in the shell model Monte Carlo method
• Parity-Projected Shell Model Monte Carlo Level Densities for fp-shell Nuclei
• Odd-particle systems in the shell model Monte Carlo: circumventing a sign problem

Cited by in corpus (8)

• Quantum Monte Carlo methods for nuclear physics
• Review on the progress in nuclear fission
• Stochastic Estimation of Nuclear Level Density in the Nuclear Shell Model: An Application to Parity-Dependent Level Density in ${}^{58}$Ni
• State densities of heavy nuclei in the static-path plus random-phase approximation
• A fully microscopic model of total level density in spherical nuclei
• Nuclear level densities: from empirical models to microscopic methods
• Recent Advances in the Microscopic Calculations of Level Densities by the Shell Model Monte Carlo Method
• Recent Advances in the Application of the Shell Model Monte Carlo Approach to Nuclei