Pairing Nambu-Goldstone Modes within Nuclear Density Functional Theory

TL;DR

This paper applies Nambu-Goldstone formalism within nuclear density functional theory to accurately describe binding-energy differences and pairing phenomena in open-shell nuclei, providing new insights into nuclear pairing correlations.

Contribution

It introduces a systematic analysis of pairing-rotational moments of inertia and offers a unified interpretation of binding-energy differences in nuclei.

Findings

Pairing-rotational moments of inertia are excellent pairing indicators.

Neutron and proton pairing modes mix in ground states of even-even nuclei.

Mass measurements of neutron-rich nuclei are crucial for constraining pairing energy functionals.

Abstract

We show that the Nambu-Goldstone formalism of the broken gauge symmetry in the presence of the $T=1$ pairing condensate offers a quantitative description of the binding-energy differences of open-shell superfluid nuclei. We conclude that the pairing-rotational moments of inertia are excellent pairing indicators, which are free from ambiguities attributed to odd-mass systems. We offer a new, unified interpretation of the binding-energy differences traditionally viewed in the shell model picture as signatures of the valence nucleon properties. We present the first systematic analysis of the off-diagonal pairing-rotational moments of inertia and demonstrate the mixing of the neutron and proton pairing-rotational modes in the ground states of even-even nuclei. Finally, we discuss the importance of mass measurements of neutron-rich nuclei for constraining the pairing energy density functional.