Successive variational approach with the tensor-optimized antisymmetrized molecular dynamics for the $^5$He nucleus

TL;DR

This paper introduces a successive variational method within the tensor-optimized antisymmetrized molecular dynamics framework to accurately describe the $^5$He nucleus, capturing short-range and tensor correlations without renormalization.

Contribution

It develops a new successive approach applying correlation operators iteratively, improving convergence and accuracy in describing $^5$He with explicit correlation function optimization.

Findings

Accurate description of $^5$He ground and excited states.

Demonstrates the importance of independent correlation function optimization.

Shows explicit contributions of correlated Hamiltonian components.

Abstract

We study $^5$He variationally as the first $p$-shell nucleus in the tensor-optimized antisymmetrized molecular dynamics (TOAMD) using the bare nucleon--nucleon interaction without any renormalization. In TOAMD, the central and tensor correlation operators promote the AMD's Gaussian wave function to a sophisticated many-body state including the short-range and tensor correlations with high-momentum nucleon pairs. We develop a successive approach by applying these operators successively with up to double correlation operators to get converging results. We obtain satisfactory results for $^5$He, not only for the ground state but also for the excited state, and discuss explicitly the correlated Hamiltonian components in each state. We also show the importance of the independent optimization of the correlation functions in the variation of the total energy beyond the condition assuming common correlation forms used in the Jastrow approach.