Natural orbital description of the halo nucleus 6He

TL;DR

This paper demonstrates that using natural orbitals in ab initio calculations of the halo nucleus 6He improves convergence by better capturing the nucleus's structure, addressing challenges in describing both short-range correlations and long-range halo properties.

Contribution

It introduces the application of natural orbitals to enhance convergence in ab initio calculations of halo nuclei, specifically 6He.

Findings

Natural orbitals improve convergence in 6He calculations.

Better representation of weakly-bound halo nucleons.

Enhanced efficiency over traditional oscillator basis.

Abstract

Ab initio calculations of nuclei face the challenge of simultaneously describing strong short-range internucleon correlations and the long-range properties of weakly-bound halo nucleons. Natural orbitals, which diagonalize the one-body density matrix, provide a basis which is better matched to the physical structure of the many-body wave function. We demonstrate that the use of natural orbitals significantly improves convergence for ab initio no-core configuration interaction calculations of the neutron halo nucleus 6He, relative to the traditional oscillator basis.