Tensor-optimized shell model with bare nucleon-nucleon interaction for 4He

TL;DR

This paper introduces the tensor-optimized shell model (TOSM) combined with the unitary correlation operator method (UCOM) to accurately describe the nuclear structure of helium-4 using bare nucleon-nucleon interactions, addressing tensor interactions.

Contribution

The paper develops and applies the tensor-optimized shell model with UCOM to handle tensor interactions and short-range correlations in helium-4, demonstrating improved accuracy over previous models.

Findings

Successful reproduction of $^4$He ground state properties

Effective handling of tensor interactions with TOSM and UCOM

Comparison shows high agreement with few-body calculations

Abstract

The pion exchange between nucleons generates a strong tensor interaction, which provides a large attractive contribution for the binding energy of nucleus. This non central tensor interaction is difficult to handle in the shell model framework, which hinders full understanding of nuclear structure. We develop the tensor-optimized shell model (TOSM) for the strong tensor interaction and now we are able to use bare nucleon-nucleon interaction with the help of the unitary correlation operator method (UCOM) for the short-range hard core. We adopt the nucleon-nucleon interaction, AV8', and calculate explicitly the ground state of $^4$He and make a detailed comparison with rigorous few-body model calculations. We show a large amount of success of the tensor-optimized shell model with bare nucleon-nucleon interaction for 4He.