[en] The various models that were successively developed for describing static nuclear deformations are reviewed. The properties of the nuclei in their ground state lead to the concept of ellipsoidal nuclei, the liquid drop model being intended to explain the deformations of the excited nucleus, the shell corrections explain the drawbacks of the liquid drop model and the Strutinski theory describes their effects on the fission barrier. The collective model, the deformed shell model and the unified model having been successively introduced to explain the rotational spectrum. The approximations involving infinite nuclear matter and effective interactions, and nuclear Hartree-Fock calculations are briefly outlined jointly with heavy ion excitation of yrast levels

[en] The decoupled νi_13/2 bandhead energies and deformations of odd-N nuclei with Z=56--64 and N=69--77 have been calculated systematically with the newly modified Nilsson parameters. The results show that the occupation of the low-K νi_13/2 orbitals does favor large deformation. Possible candidates for the experimental observation of such structures are discussed. The strong β-driving effect of those orbitals at higher frequency is examined as well

[en] The systematic behavior of β₂ values with respect to the parameter P=N_pNn/(N_p+N_n) is examined, and it is found that the rate of increase of β₂/β₂ sp as a function of P is the same in all mass regions. A new method for predicting β₂ values which exploits this relationship is described. This method is particularly useful for predicting β₂ values in a region of well-deformed nuclei where no values have yet been measured, such as the region near ¹³⁰Sm

[en] In this paper the notion of nuclear shape and its relation to the deformation parameters and symmetries is shortly discussed

[en] The equations of the coupled channel method for the calculations of the cross-section in the scattering of nucleus by nuclei without axial symmetry are obtained. An analysis of these equations is given. The possibility of using the data obtained from inelastic scattering to investigate the deformation character of nonaxial nuclei is evaluated. (author)

[en] It is shown that bifurcation may appear in the rotational band of odd deformed nuclei. It manifests itself in the fact that the levels of the favoured and unfavoured bands approach one another

No abstract available

[en] New information about rotational bands of strongly deformed nuclei as obtained through in-beam γ-spectroscopic studies as well as Coulomb excitation experiments shall be discussed. Most of the experimental results shall be interpreted within the cranking model considering the motion of independent particles in a rotating deformed potential. The relevant experimental results concern the second band crossing in yrast bands (backbending), the band crossing in side bands and the low-spin members of the s band. Experimental evidence that the backbending behaviour of the yrast bands in the Os nuclei is caused by the crossing of the g band with an isub(13/2) two-quasi-neutron band shall be provided. Furthermore a study of B(E2) values of transitions within and between rotational bands as obtained in a Coulomb excitation experiment shall be discussed. (orig.)

[en] Thr aim of the paper in to present a model based on the neutron-proton pairing vibrations for the doublets of the excited 0⁺ states that were observed in some deformed nuclei in the rare earth region. To prove our hypothesis on these states we have calculated their excitation energies using the Quasiparticle Random Phase Approximation method. (Author)

[en] The question of the appropriate choice of oscillator basis functions for studying exotic nuclear shapes is raised. Difficulties with the conventional choice of oscillator basis states are noted for shapes having a large banana component. A prescription for an improved oscillator basis to study these shapes is given. It can be applied in a more general context. New calculations with this improved basis are presented for the banana deformation mode. The change of basis gives results that improve the prospects of finding states in the banana minimum for many isotopes of Tl, Pb and Bi