# Effects of pairing, continuum, and deformation on particles in the classically forbidden regions for Mg isotopes

## TL;DR

This study investigates how pairing, continuum effects, and deformation influence particles in classically forbidden regions of Mg isotopes using a relativistic Hartree-Bogoliubov framework, revealing significant deviations in neutron halo nuclei.

## Contribution

It introduces a detailed analysis of deformation and continuum effects on particles in forbidden regions for Mg isotopes within a relativistic mean-field approach.

## Key findings

- Neutron and proton radii deviations are largest in $^{42}$Mg and $^{44}$Mg.
- Deformation increases particles in forbidden regions below the continuum threshold.
- Deeply bound states significantly contribute to particle increase due to deformation.

## Abstract

Particles in the classically forbidden regions are studied based on the deformed relativistic Hartree-Bogoliubov theory in continuum with PC-PK1 for magnesium isotopes. By analyzing the neutron and proton radii, it is found that the largest deviations from the empirical values appear at the predicted neutron halo nuclei $^{42}$Mg and $^{44}$Mg. Consistently, notable increases at $^{42}$Mg and $^{44}$Mg are found in the total number of neutrons in the classically forbidden regions that includes the number of neutrons in continuum. It is shown that the deformation effect, in general, increases the number of particles in the classically forbidden regions below the continuum threshold. The most deeply bound single-particle states play the dominant roles in the increase caused by deformation.