# Examining possible neutron-halo nuclei heaver than $^{37}$Mg

## TL;DR

This paper explores potential neutron-halo nuclei heavier than $^{37}$Mg by analyzing shell structures and deformation effects, identifying promising candidates that may exhibit deformed s-wave or p-wave halo characteristics near the neutron drip-line.

## Contribution

It introduces a theoretical framework for identifying the lightest neutron-halo nuclei heavier than $^{37}$Mg based on shell structure and deformation considerations.

## Key findings

- Potential candidates include $^{71}$Cr, $^{73}$Cr, $^{75}$Cr, and $^{77}$Fe.
- Deformed s-wave halo possibility in certain nuclei.
- Deformed p-wave or s-wave halo in $^{53}$Ar.

## Abstract

The even-Z odd-N neutron-halo nuclei, which are the possible lightest neutron-halo nuclei heavier than $^{37}$Mg, are explored by studying the shell-structure unique in weakly-bound neutrons for spherical or deformed shape. It is pointed out that due to the narrowed N=50 spherical energy-gap and a few resulting close-lying neutron one-particle levels, 1g$_{9/2}$, 3s$_{1/2}$, and 2d$_{5/2}$, for spherical shape, nuclei with some weakly-bound neutrons filling in those levels may be deformed and have a good chance to show deformed s-wave halo. Promising candidates are $^{71}_{24}$Cr$_{47}$, $^{73}_{24}$Cr$_{49}$, $^{75}_{24}$Cr$_{51}$ and $^{77}_{26}$Fe$_{51}$ in the case that those nuclei lie inside the neutron drip-line. An interesting possibility of the deformed p-wave or s-wave halo is suggested also for the nucleus $^{53}_{18}$Ar$_{35}$.