Two-phonon γ-vibrational state inEr168

Abstract
In order to identify double-γ vibrational states in well-deformed regions, we have made a Coulomb excitation experiment for Er168. We could observe 1235-keV and 962-keV γ transitions decaying from the 2056-keV 4+ state. The measured E2 transition probabilities support the assignment of the 4+ state as a two-phonon γ-vibrational state.