[en] The energy-density for the Skyrme forces in the Hartree-Fock-approximation is compared with the energy-density in the quasi-Hartree-Fock-approximation for two-body nucleon-nucleon forces with hard-core repulsion. From these expressions the magnitudes of the corresponding Hartree-Fock parameters of the nucleon-nucleon force are estimated. As an example, a simple nucleon-nucleon force is constructed, which reproduces the results of the Skyrme force SII. The ambiguities of such an comparison are discussed. The Skyrme forces SII-SIV correspond to potentials with hard-core radii approx. equal to 0.5-0.7 F. Smaller hardcore radii correspond to larger exchange contributions. (orig.)

[en] The nuclear single particle potential or the nuclear mean field is a basic ingredient for proper understanding of nucleon-nucleus scattering data at intermediate and high energies. To study the momentum, density and asymmetry dependence of the single particle potential of asymmetric nuclear matter (ANM) in non relativistic mean field approximation we have used a simple finite range effective interaction such as Yukawa, Gaussian or exponential, and specified by single range parameter α

[en] We discuss the effect of kinetic energy of the relative motion becoming spurious for separate fragments on the selfconsistent mean-field fission barriers. The treatment of the relative motion in the cluster model is contrasted with the necessity of a simpler and approximate approach in the mean-field theory. A scheme of the energy correction to the Hartree-Fock is proposed. The results obtained with the effective Skyrme interaction SLy6 show that the correction, previously estimated as ~ 8 MeV in A = 70 - 100 nuclei, amounts to 4 MeV in the medium heavy nucleus ¹⁹⁸Hg and to null in ²³⁸U. However, the corrected barrier implies a shorter fission half-life of the latter nucleus. The same effect is expected to lower barriers for multipartition (i.e. ternary fission, etc) and make hyperdeformed minima less stable. (author)

[en] Several issues related, directly or indirectly, to the Yukawa coupling in the Skyrme model are discussed. The authors try to shed a new light on the physical nature of the zero modes associated with translation (rotation) invariance of the model

[en] The nuclear fission phenomenon is a magnificent example of a quantal collective motion during which the nucleus evolves in a multidimensional space representing shapes with different geometries. The triaxial degrees of freedom are usually important around the inner fission barrier, and reduce the fission barrier height by several MeV. Beyond the inner barrier, reflection-asymmetric shapes corresponding to asymmetric elongated fragments come into play. We discuss the interplay between different symmetry breaking mechanisms in the case of even-even fermium isotopes using the Skyrme HFB formalism. (author)

[en] The response of the nuclear energy with respect to relative changes of proton versus neutron distributions is investigated. Contrary to most macroscopic-microscopic approaches, different multipole deformations of both distributions are admitted. The average part of the total energy is evaluated using the Yukawa-folded model, while microscopic energy corrections are obtained within the Strutinsky and BCS methods

[en] Barriers and spontaneous fission half lives of superheavy isotopes of Z = 112 (N = 150–190) nucleus are calculated using state dependent δ-pairing and both BCS or Lipkin-Nogami (LN) approach. Four different models of macroscopic part of Strutinsky energy are probed. Results for different macroscopic models combined with δ+LN approach give the half lives well compared to experimental data. The calculations are performed in three dimensional space of deformation parameters β = {β₂, β₄, β₆}. The probability of spontaneous fission has been obtained by dynamical action minimization method. (author)

[en] Eigenenergy expansion for the superposition of Yukawa and Gauss potentials for calculating the first indeterminacy points is derived. Behaviour of Regge trajectories for the superposed potential is also studied. (author)

[en] The accuracy of the description of the experimental heights of the fission barriers of heavy nuclei is studied. Four theoretical descriptions are considered. It is found that the average discrepancy between theoretical and experimental values for 18 even-even nuclei is about 0.8 MeV, while the largest discrepancy is about 2 MeV. (author)

[en] We review results on the structure and stability of superheavy (SH) nuclei obtained by using both Woods-Saxon (WS) model and the selfconsistent Skyrme SLy6 Hartree-Fock-BCS approach. These are occasionally contrasted with results of other models. A possibility of high-K ground states in odd and odd-odd SH nuclei is emphasized. These may well be the longest lived superheavy nuclei in view of very modest stability prospects above Z≈120. (author)