Pseudospin Conserving Shell Model Interactions

TL;DR

This paper identifies and constructs shell model interactions that approximately conserve pseudospin and pseudo-orbital angular momentum symmetries, including the effects of tensor interactions, enhancing understanding of nuclear symmetries.

Contribution

It derives shell model interactions that preserve pseudospin and pseudo-orbital angular momentum symmetries, incorporating tensor interactions and their combinations.

Findings

Certain combinations of tensor, angular momentum squared, and spin-orbit interactions conserve pseudo-orbital angular momentum.

Tensor interaction alone does not conserve pseudo-orbital angular momentum.

Shell model interactions can be constructed to approximately conserve pseudospin symmetry.

Abstract

Pseudospin symmetry is approximately conserved in nuclei. Normally shell model interactions are written in terms of spin an orbital angular momentum operators, not in terms of pseudospin and pseudo-orbital angular momentum operators. We determine the shell model interactions which conserve pseudospin symmetry and pseudo-orbital angular momentum symmetry and write them in terms of spin and orbital angular momentum operators including the tensor interaction. We show that, although the tensor interaction by itself does not conserve pseudo-orbital angular momentum, certain combinations of the tensor interaction with the two body angular momentum squared interaction and the two body spin orbit interaction do conserve pseudo-orbital angular momentum.