Microscopic investigation of $\gamma~$ vibrational band structures in odd-mass nuclei

TL;DR

This paper uses the triaxial projected shell model to systematically analyze high-spin band structures in odd-mass Nb and Tc isotopes, clarifying the nature of observed bands and predicting their properties.

Contribution

It identifies the fourth band in certain isotopes as a second gamma band, providing a detailed theoretical interpretation and predictions for these nuclear structures.

Findings

The fourth band in Nb isotopes is a second gamma band, not a 3γ band.

Transition intensity ratios support the gamma band interpretation.

Predicted excitation energies and properties for all studied nuclides.

Abstract

A systematic investigation of the high-spin band structures observed in $^{103,105,107,109}$Nb and $^{103,105,107,109}$Tc nuclides is performed using the triaxial projected shell model (TPSM) approach. For $^{103,105}$Nb isotopes, four bands have been populated with the lowest three bands corresponding to yrast, $\gamma$ and 2$\gamma$ bands. The nature of the fourth observed band has remained unresolved as it has been shown from the transition intensity ratios that this band cannot correspond to the expected 3$\gamma$ band. It is demonstrated in the present work that this fourth band is the second $\gamma$ band, resulting from the combination, $K=K_0-2$ with $K_0$ being the "$K$" value of the parent configuration. The excitation energy and other properties of this band structure are predicted for all the studied nuclides.