Superdeformation in Asymmetric N$>$Z Nucleus $^{40}$Ar

TL;DR

This paper reports the discovery of a superdeformed rotational band in the asymmetric N>Z nucleus $^{40}$Ar, characterized by specific gamma-ray transitions and supported by theoretical calculations, revealing insights into nuclear shape and structure.

Contribution

First identification of a superdeformed band in $^{40}$Ar, combining experimental gamma-ray spectroscopy with theoretical modeling to elucidate nuclear deformation and configuration.

Findings

Identification of a superdeformed rotational band in $^{40}$Ar

Measured transition quadrupole moment of 1.45 eb

Theoretical assignment of a multiparticle-multihole configuration

Abstract

A rotational band with five $\gamma$-ray transitions ranging from 2$^{+}$ to 12$^{+}$ states was identified in $^{40}$Ar. This band is linked through $\gamma$ transitions from the excited 2$^{+}$, 4$^{+}$ and 6$^{+}$ levels to the low-lying states; this determines the excitation energy and the spin-parity of the band. The deduced transition quadrupole moment of 1.45$^{+0.49}_{-0.31} eb$ indicates that the band has a superdeformed shape. The nature of the band is revealed by cranked Hartree--Fock--Bogoliubov calculations and a multiparticle--multihole configuration is assigned to the band.