Efficacy of the symmetry-adapted basis for ab initio nucleon-nucleus interactions for light- and intermediate-mass nuclei

TL;DR

This paper demonstrates that the symmetry-adapted basis combined with the resonating group method provides an effective and scalable ab initio approach for modeling nucleon-nucleus interactions across light to medium-mass nuclei.

Contribution

It introduces a novel combined framework of symmetry-adapted no-core shell-model and RGM for unified nuclear structure and reaction calculations, showing scalability and efficacy.

Findings

Effective ab initio neutron-nucleus interactions for multiple targets.

Demonstrated scalability of the symmetry-adapted basis with particle number.

Analyzed the impact of model space size on phase shifts and potentials.

Abstract

We study the efficacy of a new ab initio framework that combines the symmetry-adapted (SA) no-core shell-model approach with the resonating group method (RGM) for unified descriptions of nuclear structure and reactions. We obtain ab initio neutron-nucleus interactions for $^4$He, $^{16}$O, and $^{20}$Ne targets, starting with realistic nucleon-nucleon potentials. We discuss the effect of increasing model space sizes and symmetry-based selections on the SA-RGM norm and direct potential kernels, as well as on phase shifts, which are the input to calculations of cross sections. We demonstrate the efficacy of the SA basis and its scalability with particle numbers and model space dimensions, with a view toward ab initio descriptions of nucleon scattering and capture reactions up through the medium-mass region.