Band-like structures and quartets in deformed N=Z nuclei

TL;DR

This paper introduces a novel quartet-based formalism to describe deformed N=Z nuclei, successfully reproducing low-lying spectra and revealing band-like structures linked to specific quartet configurations.

Contribution

The study develops a variational quartet approach with intrinsic states, providing a new method to analyze deformed N=Z nuclei and their spectral band structures.

Findings

Accurate reproduction of low-lying spectra in studied nuclei.

Identification of band-like structures associated with quartet configurations.

Demonstration of the approach's effectiveness in sd and pf shells.

Abstract

We provide a description of deformed $N=Z$ nuclei in a formalism of $\alpha$-like quartets. Quartets are constructed variationally by resorting to the use of proper intrinsic states. Various types of intrinsic states are introduced which generate different sets of quartets for a given nucleus. Energy spectra are generated via configuration-iteraction calculations in the spaces built with these quartets. The approach has been applied to $^{24}$Mg and $^{28}$Si in the $sd$ shell and to $^{48}$Cr in the $pf$ shell. In all cases a good description of the low-lying spectra has been achieved. As a peculiarity of the approach, a close correspondence is observed between the various sets of quartets employed and the occurrence of well defined band-like structures in the spectra of the systems under study.