Challenge for describing the cluster states starting with realistic interaction

TL;DR

This paper develops a method to describe nuclear cluster states starting from realistic interactions, incorporating a damping factor to handle short-range correlations, and demonstrates improved reproduction of energies and structures in light nuclei.

Contribution

It introduces a damping factor approach to realistic nuclear interactions, enabling better modeling of cluster states and energies in light nuclei, including the effects of three-body forces.

Findings

The damping factor partially accounts for short-range correlations.

A finite-range three-body term improves energy predictions.

The method reproduces resonance energies and cluster structures effectively.

Abstract

We aim to describe the cluster states of nuclear systems starting with a realistic interaction, which is a challenge of modern nuclear theories. Here, the short-range correlation of realistic interaction is treated by employing the damping factor, and the resultant interaction can be applied to the cluster structure of light nuclei. We start with a realistic interaction (G3RS) and transform it in this way, and the $\alpha$-$\alpha$ energy curve is compared with the results of phenomenological interactions. The attractive effect between two $\alpha$'s is found to be not enough even with a damping factor for the short-range repulsion, and the necessity of a finite-range three-body term is discussed. With this three-body term, the resonance energy of the ground state and the scattering phase shift of two $\alpha$'s can be reproduced. Also, the binding energy of $^{16}$O from the four $\alpha$ threshold is reasonably reproduced. The linear-chain structure of three and four $\alpha$ clusters in $^{12}$C and $^{16}$O are calculated with this interaction and compared with the results of the conventional approaches including the density functional theories.