New insight on pseudospin doublets in nuclei

TL;DR

This paper explores the nature of pseudospin symmetry in nuclei, revealing new models that avoid missing states and proposing alternative pseudospin partner associations, challenging previous assumptions.

Contribution

It introduces models that allow continuous transition between spin and pseudospin symmetry without missing states, and suggests alternative pseudospin partner relationships.

Findings

Some models show no missing single-particle states during the transition.

Pseudospin partners may differ from traditional assumptions.

Strong violation of pseudospin symmetry is observed.

Abstract

The relevance of the pseudospin symmetry in nuclei is considered. New insight is obtained from looking at the continuous transition from a model satisfying the spin symmetry to another one satisfying the pseudospin symmetry. This study suggests that there are models allowing no missing single-particle states in this transition, contrary to what is usually advocated. It rather points out to an association of pseudospin partners different from the one usually assumed, together with a strong violation of the corresponding symmetry. A comparison with results obtained from some relativistic approaches is made.