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The γ-decay from excited nuclei is used to study the interplay between rotational motion and compound nucleus formation in deformed nuclei. A new analysis technique is presented which allows for the first time to directly measure the rotational and compound damping widths Γrot and Γμ from γ-coincidence spectra. The method is first tested on simulated spectra and then applied to high-statistics EUROBALL data on the nucleus 163Er. Experimental values of ≈200 and 20 keV are obtained for Γrot and Γμ, respectively, in the spin region I ≈ 30–40 h, in good agreement with microscopic cranked shell model calculations for the specific nucleus. A dependence of rotational damping on the K-quantum number of the nuclear states is also observed, both in experiment and theory, resulting in a ≈30% reduction of Γrot for high-K states. This points to a delayed onset of rotational damping in high-K configurations. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Properties of thermally excited rotating nuclei are discussed by means of the cranked shell model. Focus is put on the violation of the K-quantum number in the rare-earth deformed nucleus 163Er and on the peculiar features of rotational motion in superdeformed Hg nuclei, which appear to be precursory of ergodic rotational bands. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

The excitation energy, spin and parity of the yrast superdeformed (SD) band in 152Dy have been established. The excitation energy of the lowest observed level in this band is found to be 10,644 keV with an assigned spin and parity of 24+. In addition, nine transitions of dipole character have been identified, which connect the excited superdeformed band 6 in 152Dy to the yrast SD band. The excitation energy of the lowest level in the excited SD band 6 is 14,239 keV. The spin and parity of this state has been determined to be either 29- or 31-. The measured properties of SD band 6 are consistent with an interpretation in terms of a rotational band built on an octupole vibration. A comparison with an RPA calculation by Nakatsukasa et al. suggests that the spin of the lowest SD band 6 level is 31-. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]