Shape evolution in the rapidly rotating $^{140}$Gd nucleus

TL;DR

This paper investigates the shape evolution of the $^{140}$Gd nucleus under rapid rotation, using experimental spectroscopic data and theoretical models to reveal its triaxial deformation and rotational behavior.

Contribution

It combines experimental lifetime measurements with theoretical calculations to analyze the shape and rotational properties of $^{140}$Gd at high spin states.

Findings

The nucleus exhibits triaxiality with gamma = -30 degrees.

Level lifetimes were successfully measured using the Doppler Shift Attenuation Method.

Theoretical models suggest possible rotation around the longest principal axis at high spin.

Abstract

Ground state band of $^{140}$Gd has been investigated following their population in the $^{112}$Sn($^{35}$Cl,~$\alpha$p2n)$^{140}$Gd reaction at 195 MeV of beam energy using a large array of Compton suppressed HPGe clovers as the detection setup. Apart from other spectroscopic measurements, level lifetimes of the states have been extracted using the Doppler Shift Attenuation Method. Extracted quadrupole moment along with the pairing independent cranked Nilsson-Strutinsky model calculations for the quadrupole band reveal that the nucleus preferably attains triaxiality with $\gamma$ = -30$^\circ$. The calculation though shows a slight possibility of rotation around the longest possible principal axis at high spin $\sim$ 30$\hbar$ which is beyond the scope of the present experiment.