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

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.

Comments: 8 pages, 3 Figures, To Appear in Acta Physica Polonica B (Special Issue dedicated to Mazurian Lakes Conference 2025)