Relativistic Brueckner-Hartree-Fock theory for neutron drops

TL;DR

This paper applies relativistic Brueckner-Hartree-Fock theory to neutron drops, calculating energies and radii, and analyzing shell effects, providing insights for neutron-rich systems and future density functional development.

Contribution

It introduces a relativistic ab initio approach to neutron drops, emphasizing the role of tensor forces and shell closures, advancing understanding beyond nonrelativistic models.

Findings

Ground state energies and radii match well with other ab initio and density functional results.

Identifies magic numbers and sub-shell closures in neutron drops.

Discusses the impact of tensor force on spin-orbit and pseudospin-orbit splittings.

Abstract

Neutron drops confined in an external field are studied in the framework of relativistic Brueckner-Hartree-Fock theory using the bare nucleon-nucleon interaction. The ground state energies and radii of neutron drops with even numbers from $N = 4$ to $N=50$ are calculated and compared with results obtained from other nonrelativistic \textit{ab initio} calculations and from relativistic density functional theory. Special attention has been paid to the magic numbers and to the sub-shell closures. The single-particle energies are investigated and the monopole effect of the tensor force on the evolutions of the spin-orbit and the pseudospin-orbit splittings is discussed. The results provide interesting insight of neutron rich systems and can form an important guide for future density functionals.