Abstract
Excited states in the deformed nucleus Er-168 have been studied with high-energy resolution, in the (p,t) reaction, with the Munich Q3D spectrograph. A number of 25 excited 0(+) states (four tentative) and 63 2(+) states have been assigned up to 4.0 MeV excitation energy. This unusually rich characterization of the 0(+) and 2(+) states in a deformed nucleus, close to a complete level scheme, offers a unique opportunity to check, in detail, models of nuclear structure that incorporate many excitation modes. A comparison of the experimental data is made with two such models: the quasiparticle-phonon model (QPM), and the projected shell model (PSM). The PSM wave functions appear to contain fewer correlations than those of the QPM and than required by the data.