[en] Experimental evidence from the spectroscopy of ¹⁵⁵Gd and ¹⁵³Sm for the theoretically predicted quadruplet band structure, with band parity sequences (+--+) and (-++-), is examined. (author). 3 figs., 1 tab., 20 refs

[en] Quantum corrections to the Vlasov approach using an initial Thomas-Fermi distribution are estimated by comparing them with exact transition densities for quadrupole and octupole collective excitations in a schematic model. It is shown that corrections depend both on the dynamics and the initial state, and they were found to be relevant for the low lying states. (Author)

[en] Based on the boson expansion and the so-called Jancovici-Schiff substitution, an approach has been developed to study the microscopic foundation of the interacting boson model. In this work an extension of the approach is made, thus one is able to treat the excitations of such system in which several neutron bosons, a proton boson and a proton-hole boson exist. With the consideration of the proton two-particle two-hole excitation configurations. The authors have studied the intruder quasi-rotational bands in double-even Sn nuclei. The Calculated results are compared with experiment and some features of the configuration mixture are discussed

[en] The α-clustering in a single-level model with pairing forces dependent of spin and isospin was discussed by means of the symmetry of the boson space in the Dyson representation of the Hamiltonian. The numerical results of the ground state energy, the separation energy of the last nucleon pair, and the α-transfer rates were given

[en] The coexistence of normal and intruder states is described within the framework of the proton-neutron interacting boson model. It is shown that the excitation energy of the intruding configuration and the structure of both the normal and intruding configurations can be described without large differences between the strength of the neutron-proton quadrupole force used for either. Detailed comparison is made for ¹¹⁴Cd

[en] Data are presented which indicate the existence of F-spin multiplets for the shape-coexistent intruder states of sequences of nuclei differing by an α particle. We argue that these intruder F-spin multiplets, or, equivalently, F-spin analog states, occur because of their larger and more nearly equal values of N_πNν

[en] By including an adequate four-particle interaction in addition to the pairing interaction, global corrections between proton and neutron fluids other than two-particle correlations in deformed nuclei are induced. As a result, superfluidities of the two nuclear systems may be generated by one another and the phase structure is enriched by a new superfluid phase dominated by the so-called alpha type correlations.(authors)

[en] A realistic level density approach, consistently employed within the pre-equilibrium emission and statistical model calculations, has been tested by comparing calculated fast neutron induced reaction data with the experimental data. The consistency of the exciton state densities, involved in the pre-equilibrium emission model, and the nuclear level density has been obtained using a single set of two-fermion level density parameters.(authors)

[en] Some details on the cranking model and its application to the interpretation of the band structures of the doubly odd nucleus ¹³⁴Pr are presented. The cranking Hamiltonian without pairing correlations is derived and rotations around and perpendicular to the symmetry axis are emphasized. The introduction of the pairing correlations, the Hartree- Fock-Bogolyubov are discussed. The information provided by the transformation to the intrinsic system is presented. The knowledge of the correct single-particle spectra for analyzing the high-spin phenomena is shown to be important, the Nilsson model with axial asymmetry is described. As an illustrative application of the cranking model, the band structure of the doubly odd nucleus ¹³⁴Pr is discussed.(authors)

[en] The present work is focused on the use and evaluation, mainly in RPA, of sum rules for the study of systematic properties of the excitation spectrum of nuclear collective states. Characterizations of the linear response function, and of integral properties of the excitation strength function via a moment expansion are discussed. Sum rules expressions for the moments are derived both for exact solutions of H and for approximate solutions in RPA, with a special emphasis on the differences between isoscalar and isovector excitations. For forces of the Skyrme type, analytic expressions for the plus one (isoscalar and isovector excitations) and plus three (isoscalar excitation) energy weighted sum rules are given for monopole, dipole and quadrupole operators. The inverse energy weighted sum rules is discussed in the scale approximation.(author)