Microscopic investigation of wobbling motion in atomic nuclei using the triaxial projected shell model approach

TL;DR

This paper uses the triaxial projected shell model to systematically analyze wobbling motion in various odd-mass nuclei, revealing transverse and longitudinal wobbling modes and matching experimental data well.

Contribution

It applies the TPSM approach to a wide range of nuclei, providing new insights into wobbling modes and electromagnetic transition behaviors in nuclear structure.

Findings

Most studied nuclei exhibit transverse wobbling mode.

Some nuclei show increasing wobbling frequency with spin, indicating longitudinal wobbling.

Electromagnetic transitions are predominantly E2, not M1.

Abstract

A systematic investigation of the wobbling band structures observed in odd-mass nuclei of $^{161,163,165,167}$Lu, $^{167}$Ta $^{131}$Cs, $^{135}$Pr, $^{151}$Eu, $^{183}$Au, $^{133}$Ba, $^{105}$Pd, $^{133}$La, $^{187}$Au and $^{127}$Xe is performed using the triaxial projected shell model (TPSM) approach. It is demonstrated that all the studied band structures have transverse wobbling mode, except for $^{133}$La, $^{187}$Au (negative parity), $^{183}$Au (positive parity) and $^{127}$Xe nuclei where the wobbling frequency increases with spin, indicating that the collective motion has a longitudinal character. To elucidate further the wobbling nature of the band structures, electromagnetic transition probabilities have been evaluated and it is observed that inter-band transitions are dominated by $E2$ rather than $M1$ as expected for a typical signature partner band. It is shown that TPSM approach provides a reasonable description of all the measured properties of the studied nuclei.