Is $^{40}$Mg a Borromean halo nucleus? A case built on the electric-dipole response

TL;DR

This paper explores whether $^{40}$Mg is a Borromean halo nucleus by analyzing its low-energy electric-dipole response through a three-body model considering different neutron-neutron interactions.

Contribution

It introduces a detailed three-body hyperspherical model to study $^{40}$Mg's electric-dipole response, comparing effects of different neutron-neutron interactions.

Findings

Electric-dipole response varies with neutron-neutron interaction type

The model provides insights into the halo nature of $^{40}$Mg

Results suggest $^{40}$Mg exhibits characteristics of a Borromean halo nucleus

Abstract

We investigate the low-energy electric-dipole response of $^{40}$Mg using a $^{38}$Mg$+n+n$ three-body model. This model is implemented using a three-body hyperspherical formalism with an analytical transformed harmonic oscillator basis. In this study, two different neutron-neutron interactions are considered: a scalar Gaussian density-dependent central potential and a more realistic finite-range potential which includes central, spin-orbit, and tensor components. We examine how electric-dipole response is affected by the choice of the interaction.