Matter and charge radius of 6He in the hyperspherical-harmonics approach

TL;DR

This paper uses an ab-initio hyperspherical harmonics approach with chiral EFT interactions to accurately calculate the matter and charge radii of the halo nucleus 6He, highlighting the importance of three-nucleon forces.

Contribution

It introduces an effective interaction to improve convergence in hyperspherical harmonics calculations of 6He using chiral EFT potentials, emphasizing the role of three-nucleon forces.

Findings

Converged calculations of 6He radii using hyperspherical harmonics.

Correlation between radii and two-neutron separation energy.

Three-nucleon forces significantly affect results.

Abstract

We present ab-initio calculations of the binding energy and radii of the two-neutron halo nucleus 6He using two-body low-momentum interactions based on chiral effective field theory potentials. Calculations are performed via a hyperspherical harmonics expansion where the convergence is sped up introducing an effective interaction for non-local potentials. The latter is essential to reach a satisfactory convergence of the extended matter radius and of the point-proton radius. The dependence of the results on the resolution scale is studied. A correlation is found between the radii and the two-neutron separation energy. The importance of three-nucleon forces is pointed out comparing our results and previous calculations to experiment.