Multi-Phonon $\gamma$-Vibrational Bands and the Triaxial Projected Shell Model

Abstract

We present a fully quantum-mechanical, microscopic, unified treatment of ground-state band and multi-phonon $\gamma$-vibrational bands using shell model diagonalization with the triaxial projected shell model. The results agree very well with data on the g- and $\gamma$-band spectra in ${}^{156-170}$Er, as well as with recently measured $4^{+}$ 2-phonon $\gamma$-bandhead energies in ${}^{166}$Er and ${}^{168}$Er. Multi-phonon $\gamma$-excitation energies are predicted.

Comments: 4 pages, 4 figures, submitted to Phys. Lett. B