The cluster-core model for halo-structure of light nuclei at the drip lines

TL;DR

This paper introduces a cluster-core model to analyze halo structures in light nuclei at the drip lines, predicting potential energy surfaces and identifying new magic numbers and molecular structures.

Contribution

The study develops a simple potential energy surface approach to predict halo structures and magic numbers in exotic nuclei, extending understanding beyond existing hypotheses.

Findings

Model predictions align with experimental data for halo nuclei.

N=6 identified as a new magic number for neutron-deficient nuclei.

Z=N=2 and Z=8 remain magic near the drip line.

Abstract

Nuclei at both the neutron- and proton-drip lines are studied. In the cluster-core model, the halo-structure of all the observed and proposed cases of neutron- or proton-halos is investigated in terms of simple potential energy surfaces calculated as the sum of binding energies, Coulomb repulsion, nuclear proximity attraction and the centrifugal potential for all the possible cluster+core configurations of a nucleus. The clusters of neutrons and protons are taken to be unbound, with additional Coulomb energy added for proton-clusters. The model predictions agree with the available experimental studies but show some differences with the nucleon separation energy hypothesis, particularly for proton-halo nuclei. Of particular interest are the halo-structures of $^{11}N$ and $^{20}Mg$. The calculated potential energy surfaces are also useful to identify the new magic numbers and molecular structures in exotic nuclei. In particular, N=6 is a possible new magic number for very neutron-deficient nuclei, but Z=N=2 and Z=8 seem to remain magic even for such nuclei, near the drip line.