[en] The phenomenon of identical bands is studied by analyzing the distributions of fractional changes in the dynamical moments of inertia of pairs of bands in superdeformed (SD) nuclei. These distributions are found to exhibit a peak with a centroid at nearly zero. Their widths increase in going from the SD bands in the mass A ∼ 150, to the SD bands in the mass ∼190 and to the normally-deformed bands in the rare-earth region. These differences may be attributed to the weaker pairing correlations and the stabilizing role of intruder orbitals on the structures of SD bands. Precise level lifetimes have been measured for various pairs of identical SD bands in Gd and Dy isotopes. By comparing the derived quadrupole moments with calculations performed in the framework of the cranking Skyrme-Hartree-Fock model, it is shown that, independently of the intrinsic configuration and of the proton and neutron numbers, the charge moments calculated with respect to the doubly-magic SD core of ¹⁵²Dy can be expressed in terms of independent contributions from the individual hole and particle orbitals. (author)

[en] The Table of Superdeformed Nuclear Bands and Fission Isomers contains all experimental data on the nuclear structure of superdeformed bands published through October, 2002. Level schemes, moment of inertia plots, and data tables are presented. A complete reference list is provided

No abstract available

[en] Originally, random matrix theory (RMT) was designed by Wigner to deal with the statistics of eigenvalues and eigenfunctions of complex many-body quantum systems in 1950s. During the last two decades, the RMT underwent an unexpected and rapid development: The RMT has been successfully applied to an ever increasing variety of physical problems, and it has become an important tool to attack many-body problems. In this contribution I briefly outline the development of the RMT and introduce its basics. Its application to the decay out of a superdeformed band and a comparison of the approach used in Ref. 34 with that proposed by Vigezzi et al are presented. Current theoretical activities on the decay out problem are reviewed, and the influence of the degree of chaoticity of the normally deformed states on the decay out intensity is examined systematically. (author)

[en] An interconnection between quantum bifurcations and quantum phase transitions is investigated. It is shown that the quantum phase transition is the limiting case of the quantum bifurcation in macroscopic systems. Critical phenomena in microscopic many-body systems such as nuclei, molecules, etc. are described by quantum bifurcations. They are characterized by a large transition region, which conceals a critical point. Both the quantum bifurcation and quantum phase transition show that a change in the internal structure of a system manifests itself in the modification of its rotational spectrum. Such an intimate connection between internal and rotational motion allows a critical phenomenon to be established

[en] We discuss some characteristic features of the wobbling motion excited on the triaxial superdeformed Lu and Hf nuclei. We show these features are determined by the behavior of the moments of inertia

[en] A new island of superdeformed nuclei with major-to-minor axis ratio of 2:1 has recently been discovered in the A ∼ 80 medium-mass region, confirming the predictions for the existence of a large SD gap at particle number N,Z ∼ 44. The general properties of more than 20 bands observed so far will be reviewed here, and compared with those of the superdeformed bands in the heavier nuclei

[en] A new expression for the branching ratio for the decay via the E1 process in the normal-deformed band of superdeformed nuclei is given within a simple two-level model. Using this expression, the spreading or tunneling width Γ^↓ for superdeformed decay can be expressed entirely in terms of experimentally known quantities. We show how to determine the tunneling matrix element V from the measured value of Γ^↓ and a statistical model of the energy levels. The accuracy of the two-level approximation is verified by considering the effects of the other normal-deformed states

[en] In reply to the Comment by Heyde et al., we discuss the sensitivity of the results of relativistic mean field (RMF) calculations on the shape of nuclei to the choice of input parameters in the Lagrangian of the σ,ω,ρ model and to the pairing gap in the BCS theory. copyright 1996 The American Physical Society

[en] Within the supersymmetry scheme including many-body interactions and a perturbation possessing the SO(5) (or SU(5)) symmetry on the rotational symmetry, the superdeformed (SD) bands of the odd-A nuclei in A≅190 mass region are investigated systematically. Quantitatively good results of the γ-ray energy spectra and the dynamical moments of inertia are obtained. It shows that the supersymmetry approach is powerful in describing not only the generic rotational property , but also the ΔI=4 bifurcation and the identical bands in SD states simultaneously. (author)