Covariant Density Functional Theory with Localized Exchange Terms

TL;DR

This paper introduces a new covariant density functional, PCF-PK1, with localized exchange terms, improving the description of nuclear properties and eliminating spurious shell closures, while accurately reproducing Gamow-Teller resonances.

Contribution

The paper develops a novel density functional with local exchange terms using Fierz transformation, enhancing predictive power for nuclear structure and resonances.

Findings

Eliminates spurious shell closures at Z=58 and Z=92

Accurately reproduces Gamow-Teller resonances without adjustable parameters

Provides a unified description of nuclear matter and finite nuclei

Abstract

A new density-dependent point-coupling covariant density functional PCF-PK1 is proposed, where the exchange terms of the four-fermion terms are local and are taken into account with the Fierz transformation. The coupling constants of the PCF-PK1 functional are determined by empirical saturation properties and ab initio equation of state and proton-neutron Dirac mass splittings for nuclear matter as well as the ground-state properties of selected spherical nuclei. The success of the PCF-PK1 is illustrated with properties of the infinite nuclear matter and finite nuclei including the ground-state properties and the Gamow-Teller resonances. In particular, the PCFPK1 eliminates the spurious shell closures at Z = 58 and Z = 92, which exist commonly in many covariant density functionals without exchange terms. Moreover, the Gamow-Teller resonances are nicely reproduced without any adjustable parameters, and this demonstrates that a self-consistent description for the Gamow-Teller resonances can be achieved with the localized exchange terms in the PCF-PK1. ?