Global-Vector Representation of the Angular Motion of Few-Particle Systems II

TL;DR

This paper extends a global vector method to describe both natural and unnatural parity states in few-particle systems, demonstrating its effectiveness through numerical examples involving nucleons and alpha particles.

Contribution

It introduces an extended global vector approach capable of describing unnatural parity states, improving the analysis of few-particle quantum systems.

Findings

Good agreement with other methods in numerical examples

Clarification of the role of tensor force in unnatural parity states

Distinct characteristics of interactions shown via correlation functions

Abstract

The angular motion of a few-body system is described with global vectors which depend on the positions of the particles. The previous study using a single global vector is extended to make it possible to describe both natural and unnatural parity states. Numerical examples include three- and four-nucleon systems interacting via nucleon-nucleon potentials of AV8 type and a 3$\alpha$ system with a nonlocal $\alpha\alpha$ potential. The results using the explicitly correlated Gaussian basis with the global vectors are shown to be in good agreement with those of other methods. A unique role of the unnatural parity component, caused by the tensor force, is clarified in the $0^-_1$ state of $^4$He. Two-particle correlation function is calculated in the coordinate and momentum spaces to show different characteristics of the interactions employed.