Nuclear Dynamics and Reactions in the Ab Initio Symmetry-Adapted Framework

TL;DR

This paper reviews the ab initio symmetry-adapted framework for nuclear structure and reactions, emphasizing the role of symplectic symmetry in understanding collective nuclear dynamics across various isotopes.

Contribution

It introduces a unified symmetry-based approach that captures collective behaviors in nuclei from first principles, extending to continuum states and reaction processes.

Findings

Demonstrates emergence of symplectic symmetry in nuclei from first principles.

Accurately predicts energies, electromagnetic properties, and reaction observables.

Provides a comprehensive framework for nuclear structure and reactions.

Abstract

We review the ab initio symmetry-adapted (SA) framework for determining the structure of stable and unstable nuclei, along with related electroweak, decay and reaction processes. This framework utilizes the dominant symmetry of nuclear dynamics, the shape-related symplectic Sp(3,R) symmetry, which has been shown to emerge from first principles and to expose dominant degrees of freedom that are collective in nature, even in the lightest species or seemingly spherical states. This feature is illustrated for a broad scope of nuclei ranging from helium to titanium isotopes, enabled by recent developments of the ab initio symmetry-adapted no-core shell model expanded to the continuum through the use of the SA basis and that of the resonating group method. The review focuses on energies, electromagnetic transitions, quadrupole and magnetic moments, radii, form factors, and response function moments, for ground-state rotational bands and giant resonances. The method also determines the structure of reaction fragments that is used to calculate decay widths and alpha-capture reactions for simulated x-ray burst abundance patterns, as well as nucleon-nucleus interactions for cross sections and other reaction observables.