Multiphonon gamma-vibrational bands and the triaxial projected shell model- art. no. 064323

We present a fully quantum-mechanical, microscopic, unified treatment of gr ound-state band and multiphonon gamma-vibrational bands using shell model d iagonalization with the triaxial projected shell model. The results, which agree very well with data on the g- and gamma-band spectra in Er156-170, as well as with recently measured 4(+) two-phonon gamma-bandhead energies in Er-166 and Er-168, are discussed in terms of the K mixing. Multiphonon gamm a-excitation energies are predicted.