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No abstract available

[en] Structure of energy spectra and backbending phenomena of the isotope string of H_f with mass number between 162 and 170 have been investigated. Extend of SU(3)-limits of interacting boson model to allow a boson to break to form a quasiparticle pair, which can occupy h_11/2 and i_13/2 orbitals. The calculated energy levels, intensity of the electromagnetic transitions, including the ground state, β and γ band are in satisfactory agreement with observed values for the whole string of H_f isotopes. Backbending of the moment inertia of the yrast and β bands can be reproduced reasonably. Recently, very high spin states up to J=40 and a double backbending have been observed in some nuclei in rare-earth region. This phenomena might hopefully be interpreted by considering two or more bosons to break to form more quasiparticle pairs and make more bands crossing to form the double backbending

[en] Full text: Collective Schrodinger equations are applied to describe low-energy spectra of even-even nuclei [1]. Spectra for even-odd nuclei are calculated by coupling the single particle degrees of freedom to the collective degree of freedom of the core nucleus, which is of even-even type. The collective spin has a value of 3/2. This leads to the assumption that the linearized equation may be applied to describe nuclei with spin 3/2 in the ground state. Good description of the low energy spectra and electromagnetic transition probabilities can be obtained only with introduction of spin-dependent potentials, which apart from coordinates and momenta also depend on the matrices of the Clifford algebra arising in the linearization,. The interacting boson-fermion models (IBFM) [2] represent another approach to describe spectra of even-odd nuclei. For even-odd nuclei with spin 3/2 in the ground state one uses so-called j=3/2 - IBFM, which is also denoted as the U_B(6)xU_F(4) IBFM. In this paper we establish the relation between the matrices of the Clifford algebra, which arise in the linearization procedure, and the fermion operators of the j=3/2 IBFM. This allows us to establish a connection between the j=3/2 IBFM and spin dependent generalized collective model (SGCM). The results of the SGCM for Ir and Au nuclei are presented and compared with the results of the j=3/2 IBFM with a dynamical spin symmetry [3] present. In this respect we could apply the linearized collective Schrodinger equation and IBFM with arbitrary spin to all other even-odd nuclei. (author)

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[en] Full text: Bosonic and fermionic descriptions for the nuclear many body system are complementary. Without distinguishing between proton and neutron bosons, it gave rise to a successful phenomenology for medium and heavy nuclei, and is built from the concept of dynamical symmetry whose genesis is a group chain. The fermionic algebra, on the other hand, such as the fermion dynamical symmetry model (FDSM) [1], is necessarily more complex because it originates from the shell structure and uses protons and neutrons as building blocks. In this picture, it lacks the phenomenological freedom to separate the normal states from the exotic states and they should all be eigenstates of a Hamiltonian whose dominate feature must emphasize the intricate interplay between the long-range n-p quadrupole force and the short- range n-n and p-p pairing forces. Therefore the Hamiltonian is not symmetric under proton- neutron exchange. In the fermion description, the n-p quadrupole interaction responsible for splitting these types of state and give rise to two classes of states. One class is invariant under the exchange of the protons and neutrons. These states are referred as 'normal'. Another class is not invariant under the exchange and they are referred to as 'exotic' or 'mixed-symmetry' states. As an example, we examine the spectrum and electromagnetic properties of ¹³⁴Ba and ¹⁹⁶Os. (author)

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[en] In the present work the transition nuclei structure in the fermion dynamical-symmetrical model (FDSM) and in the it mappings in boson space have been considered. Sp^v(6)·SO^π(8) symmetry of FDSM and its some asymptotical limits are used to description of ^190,192,194Pt heavy isotopes states. Energies of level bands of excitation up to 5 MeV and values of B(E2) for ¹⁹⁴Pt nucleus are calculated. The calculated values are compared with experimental data and also with theoretical values found by numerical diagonalization of SU(6) boson Hamiltonian

[en] In the suggested work results of recently developed fermion-symmetrical model in comparison with mapped boson symmetry with reference to some heavy nuclei of complex structure are given. Application of the theory to nuclear state structure study within Z=50-82 field has been discussed in detail

[en] In the paper the mapping of fermion dynamical-symmetrical model (FDSM) on the Boson space is considered. By the Daison mapping method a generalized fermion operators of FDSM were obtained