Revisiting nuclear chirality in $^{128}$Cs with relativistic configuration-interaction density functional theory

Abstract

Nuclear chirality in $^{128}$Cs is revisited within the microscopic relativistic configuration-interaction density functional (ReCD) theory. The positive-parity doublet bands are investigated by simultaneously examining their energy spectra, electromagnetic transition probabilities, $g$ factors, spectroscopic quadrupole moments, and underlying angular-momentum geometry. Without introducing additional parameters adjusted to the spectroscopic data, the ReCD calculations provide an overall satisfactory description of the available experimental observables. In particular, a comprehensive analysis of the available experimental data and the calculated spectroscopic observables indicates qualitative resemblances between the partner bands around $I = 17\hbar$. A microscopic analysis of the angular-momentum geometry through \textit{azimuthal plots} reveals a distinct evolution of the rotational mode with increasing spin: chiral vibration at $I < 17\hbar$, static chirality at $I = 17\hbar$, and a transition toward planar rotation at higher spins. These results suggest that static chiral geometry in $^{128}$Cs is confined to a narrow spin region around $I = 17\hbar$ within the present ReCD calculations.