The role of superfluidity in nuclear incompressibilities

TL;DR

This paper investigates how superfluidity influences nuclear incompressibility, showing that pairing correlations make nuclei more compressible and highlighting the importance of self-consistent models for accurate predictions.

Contribution

It introduces a fully self-consistent approach to study superfluidity's effect on nuclear incompressibility using GMR in Tin isotopes, emphasizing the role of pairing correlations.

Findings

Superfluidity favors nuclear compressibility.

Pairing explains stiffness differences in nuclei.

Self-consistent GMR predictions are essential.

Abstract

Nuclei are propitious tools to investigate the role of the superfluidity in the compressibility of a Fermionic system. The centroid of the Giant Monopole Resonance (GMR) in Tin isotopes is predicted using a constrained Hartree-Fock Bogoliubov approach, ensuring a full self-consistent treatment. Superfluidity is found to favour the compressibitily of nuclei. Pairing correlations explain why doubly magic nuclei such as $^{208}$Pb are stiffer compared to open-shell nuclei. Fully self-consistent predictions of the GMR on an isotopic chain should be the way to microscopically extract both the incompressibility and the density dependence of a given energy functional. The macroscopic extraction of K$_{sym}$, the asymmetry incompressibility, is questioned. Investigations of the GMR in unstable nuclei are called for. Pairing gap dependence of the nuclear matter incompressibility should also be investigated.