Relativistic Mean-Field and Beyond Approaches for Deformed Hypernuclei

TL;DR

This paper discusses advanced theoretical approaches to understanding the structure of deformed hypernuclei, highlighting how hyperons influence nuclear properties and the importance of interaction parameters on astrophysical predictions.

Contribution

It introduces beyond mean-field methods for hypernuclear structure and analyzes hyperon effects on nuclear collectivity and state energies.

Findings

Hyperons affect nuclear quadrupole collectivity.

Large configuration mixing occurs in hypernuclear low-lying states.

Energy predictions are sensitive to $N \\Lambda$ interaction parameters.

Abstract

We report the recent progress in relativistic mean-field (RMF) and beyond approaches for the low-energy structure of deformed hypernuclei. We show that the $\Lambda$ hyperon with orbital angular momentum $\ell=0$ (or $\ell>1$) generally reduces (enhances) nuclear quadrupole collectivity. The beyond mean-field studies of hypernuclear low-lying states demonstrate that there is generally a large configuration mixing between the two components $[^{A-1}Z (I^+) \otimes \Lambda p_{1/2}]^J$ and $[^{A-1}Z (I\pm2 ^+) \otimes \Lambda p_{3/2}]^J$ in the hypernuclear $1/2^-_1, 3/2^-_1$ states. The mixing weight increases as the collective correlation of nuclear core becomes stronger. Finally, we show how the energies of hypernuclear low-lying states are sensitive to parameters in the effective $N \Lambda $ interaction, the uncertainty of which has a large impact on the predicted maximal mass of neutron stars.