Deformation of Ne isotopes in the island-of-inversion region

TL;DR

This study investigates the deformation of Neon isotopes in the island-of-inversion region using a double-folding model and AMD calculations, revealing significant deformation and halo structure in $^{31}$Ne, with implications for modeling nuclear densities.

Contribution

The paper introduces a combined approach using AMD and a deformed Woods-Saxon model to accurately simulate Neon isotope densities and deformation in the island-of-inversion region.

Findings

Reaction cross sections are well reproduced without adjustable parameters.

$^{31}$Ne is identified as a halo nucleus with large deformation.

Deformation around 0.4 is found in the island-of-inversion region.

Abstract

The deformation of Ne isotopes in the island-of-inversion region is determined by the double-folding model with the Melbourne $g$-matrix and the density calculated by the antisymmetrized molecular dynamics (AMD). The double-folding model reproduces, with no adjustable parameter, the measured reaction cross sections for the scattering of $^{28-32}$Ne from $^{12}$C at 240MeV/nucleon. The quadrupole deformation thus determined is around 0.4 in the island-of-inversion region and $^{31}$Ne is a halo nuclei with large deformation. We propose the Woods-Saxon model with a suitably chosen parameterization set and the deformation given by the AMD calculation as a convenient way of simulating the density calculated directly by the AMD. The deformed Woods-Saxon model provides the density with the proper asymptotic form. The pairing effect is investigated, and the importance of the angular momentum projection for obtaining the large deformation in the island-of-inversion region is pointed out.