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arXiv · 2501.19037

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

L. Heitz·J. P. Ebran·E. Khan
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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.

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L. Heitz, J. P. Ebran, E. Khan. 2025-01-31. Patterns of spin and pseudo-spin symmetries in nuclear relativistic mean-field approaches. https://arxiv.org/abs/2501.19037

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