From superdeformation to extreme deformation and clusterization in the N~Z nuclei of the A~40 mass region

TL;DR

This paper uses covariant density functional theory to identify highly deformed nuclear structures in A~40 nuclei, highlighting their potential observability via future gamma-ray detectors and exploring clusterization and extreme deformation phenomena.

Contribution

It provides the first systematic theoretical analysis of extremely deformed shapes in N~Z A~40 nuclei, linking them to experimental observability and clusterization features.

Findings

Highly deformed structures are located at high excitation energies at zero spin.

Rotation can bring these structures to the yrast line, making them observable.

Addition of spin can induce transitions to hyper- and megadeformed shapes.

Abstract

A systematic search for extremely deformed structures in the N~Z nuclei of the A~40 mass region has been performed for the first time in the framework of covariant density functional theory. At spin zero such structures are located at high excitation energies which prevents their experimental observation. The rotation acts as a tool to bring these exotic shapes to the yrast line or its vicinity so that their observation could become possible with future generation of $\gamma-$tracking (or similar) detectors such as GRETA and AGATA. The major physical observables of such structures (such as transition quadrupole moments as well as kinematic and dynamic moments of inertia), the underlying single-particle structure and the spins at which they become yrast or near yrast are defined. The search for the fingerprints of clusterization and molecular structures is performed and the configurations with such features are discussed. The best candidates for observation of extremely deformed structures are identified. For several nuclei in this study (such as $^{36}$Ar), the addition of several spin units above currently measured maximum spin of $16\hbar$ will inevitably trigger the transition to hyper- and megadeformed nuclear shapes.