English

Patterns of spin and pseudo-spin symmetries in nuclear relativistic mean-field approaches

Nuclear Theory 2025-02-03 v1

Abstract

The behavior of spin doublets is known to play a major role in nuclear structure and shell effects. Pseudo-spin doublets are also known to impact the single-particle spectrum. The covariant framework, having these two effects encoded in its approach, is an excellent tool to understand the main mechanism driving theses spin and pseudo-spin symmetries and their breaking. A perturbative expansion of the degeneracy raising related to spin and pseudo-spin effects is proposed, up to second order. It allows to understand the main behavior of spin and pseudo-spin energy doublets, such as their A dependence, as well as their common footing and differences. In the case of the spin symmetry, only the lower component of the Dirac bi-spinor is involved, whereas in the case of the pseudo-spin one, both the upper and lower components are involved. Their interplay with the covariant potentials is also analyzed.

Keywords

Cite

@article{arxiv.2501.19037,
  title  = {Patterns of spin and pseudo-spin symmetries in nuclear relativistic mean-field approaches},
  author = {L. Heitz and J. P. Ebran and E. Khan},
  journal= {arXiv preprint arXiv:2501.19037},
  year   = {2025}
}