Spin symmetry in the Dirac sea derived from the bare nucleon–nucleon interaction

Shihang Shen,Haozhao Liang,Jie Meng,Peter Ring,Shuangquan Zhang

doi:10.1016/j.physletb.2018.03.080

Abstract

The spin symmetry in the Dirac sea has been investigated with relativistic Brueckner–Hartree–Fock theory using the bare nucleon–nucleon interaction. Taking the nucleus 16O as an example and comparing the theoretical results with the data, the definition of the single-particle potential in the Dirac sea is studied in detail. It is found that if the single-particle states in the Dirac sea are treated as occupied states, the ground state properties are in better agreement with experimental data. Moreover, in this case, the spin symmetry in the Dirac sea is better conserved and it is more consistent with the findings using phenomenological relativistic density functionals.

Highlights

By starting from the Dirac equation, it was found that the angular momentum of the pseudospin doubletsl is nothing but the orbital angular momentum of the lower component of the Dirac spinor, and the pseudospin symmetry is exact when the sum of vector and scalar potential V + S vanishes [5]
It was shown in Ref. [27] that the pseudospin symmetry in the positive spectrum has the same origin as the spin symmetry in the Dirac sea
The SO doublets in the Dirac sea has the quantum number (n, ̃l, j = ̃l ± 1/2), and the spin symmetry breaking term is proportional to d(V + S)/dr, similar to the pseudospin symmetry in the positive spectrum

Summary

Introduction

By starting from the Dirac equation, it was found that the angular momentum of the pseudospin doubletsl is nothing but the orbital angular momentum of the lower component of the Dirac spinor, and the pseudospin symmetry is exact when the sum of vector and scalar potential V + S vanishes [5]. The spin symmetry in the Dirac sea has been investigated with relativistic Brueckner-HartreeFock theory using the bare nucleon-nucleon interaction.

Results

Conclusion