Temperature Dependence of Pair Correlations in Nuclei in the Iron-Region

Abstract

We use the shell model Monte Carlo approach to study thermal properties and pair correlations in ${}^{54,56,58}$Fe and in ${}^{56}$Cr. The calculations are performed with the modified Kuo-Brown interaction in the complete $1p0f$ model space. We find generally that the proton-proton and neutron-neutron $J=0$ pairing correlations, which dominate the ground state properties of even-even nuclei, vanish at temperatures around 1 MeV. This pairing phase transition is accompanied by a rapid increase in the moment of inertia and a partial unquenching of the M1 strength. We find that the M1 strength totally unquenches at higher temperatures, related to the vanishing of isoscalar proton-neutron correlations, which persist to higher temperatures than the pairing between like nucleons. The Gamow-Teller strength is also correlated to the isoscalar proton-neutron pairing and hence also unquenches at a temperature larger than that of the pairing phase transition.

RevTeX and ps figures

Cited by in corpus (16)

• Pairing in nuclear systems: from neutron stars to finite nuclei
• Local Density Approximation for proton-neutron pairing correlations. I. Formalism
• Overview of Neutron-Proton Pairing
• Cranked shell model and isospin symmetry near N=Z
• Pairing correlations in N~Z pf-shell nuclei
• Large-scale prediction of the parity distribution in the nuclear level density and application to astrophysical reaction rates
• Pairing transitions in the finite-temperature relativistic Hartree-Bogoliubov theory
• Results from Shell Model Monte Carlo Studies
• Thermodynamical properties of a mean-field plus pairing model and applications for the Fe nuclei
• On the temperature dependence of the symmetry energy
• Theoretical description of fission yields: towards a fast and efficient global model
• Nuclear superfluidity at finite temperature
• Symmetry Restoration in Mixed-Spin Paired Heavy Nuclei
• Pairing correlations and eigenvalues of two-body density matrix in atomic nuclei
• Pairing in Nuclear Matter and Finite Nuclei
• Quasideuterons in Light Nuclei