Low and high spin states in rare earth nuclei- a theoretical study using the projected shell model

The projected shell model is a shell model truncated in a deformed basis. In this paper, we investigate how the effective interactions are related to the truncation of the Hilbert space and how the deformed basis affects the final diagonalization. We show that self-consistency conditions between the quadrupole force and the mean field deformation must be fulfilled in order to reproduce experimental data. By a systematic study of the yrast band in 154-164 Dy isotopes we show also that, in the context of the present model, enlarging the mean field deformation by about 20 % allows a very good description of the spectrum of yrast band in these isotopes. Finally, we demonstrate that the description of soft rare earth moments of inertia can be greatly improved if a tri axially deformed basis is used. (Author)