Identification of the γ-vibrational band built on the 11/2 -[505] orbital in 165Er

Excited states in Er-165 have been populated using the Gd-160(Be-9, 4n) reaction at beam energies of 42 and 45 MeV. A band consisting of two levels at excitation energies of 1317.6 and 1505.9 keV, both of which decay strongly to the 11/2(-)[505] band, is observed and assigned as the gamma-vibrational band built on the 11/2(-)[505] configuration. In addition, a newly identified level is proposed as a three-quasiparticle state.