Yu. S. Lutostansky

First applications of the Fayans functional to deformed nuclei

First calculations for deformed nuclei with the Fayans functional are carried out for the uranium and lead isotopic chains. The ground state deformations and deformation energies are compared to Skyrme-Hartree-Fock-Bogolyubov results of HFB-17 and HFB-27 functionals. For the uranium isotopic chain, the Fayans functional predictions are rather similar properties compared to HFB-17 and HFB-27. However, there is a disagreement for the lead isotopic chain. Both of the Skyrme HFB functionals predict rather strong deformations for the light Pb isotopes which does not agree with the experimental data on charge radii and magnetic moments of the odd Pb isotopes. On the other hand, the Fayans functional predicts a spherical ground state for all of the lead isotopes, in accordance with the data and the known in literature results obtained with the Gogny D1S force and SLy6 functional as well. The deformation energy curves are calculated and compared to four Skyrme functionals, SLy4, Sly6, SkM* and UNEDF1, for

Self-consistent calculations of alpha-decay energies

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Probabilities of delayed processes for nuclei involved in the r-process

U nucleus and several lead deficient Pb isotopes. In the first case, the Fayans functional result is rather close to SkM* and UNEDF1 which, in particularly the latter one, describe the first and second barriers in

Resonance structure of the beta-strength function

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The Concept of a Powerful Antineutrino Source

U rather well. For the light lead isotopes, the Fayans deformation energy curves are qualitatively close to those of the SLy6 functional.

Alpha-decay energies of superheavy nuclei for the Fayans functional

On the basis of the self-consistent theory of finite Fermi systems, the energies of alphadecay chains were calculated for several new superheavy nuclei discovered recently in experiments of the Dubna-Livermore Collaboration headed by Yu.Ts. Oganessian. The approach in question is implemented on the basis of the generalized method of the density functional proposed by Fayans and his coauthors. The version used here relies on the functional DF3-a proposed recently for describing a wide array of nuclear data, including data on superheavy nuclei. A detailed comparison of the results obtained on this basis with the predictions of different approaches, including the self-consistent Skyrme-Hartree-Fock method, the micro-macro method in the version developed by Sobiczewski and his coauthors, and the phenomenological method of Liran and his coauthors, is performed. The resulting alpha-decay energies are used to calculate respective lifetimes with the aid of the phenomenological Parkhomenko-Sobiczewski formula.

Restoration of Wigner supersymmetry in heavy and superheavy nuclei

Delayed fission, along with induced and spontaneous fission, is responsible for the suppression of the production of superheavy elements both during the r-process and after its completion. Beta-decay strength functions are required for calculating delayed fission. In the present study, respective strength functions are calculated by relying on the theory of finite Fermi systems and by predominantly employing nuclear masses and fission barriers predicted by a generalized Thomas-Fermi model. The probabilities for delayed fission and for the emission of delayed neutrons are calculated for a number of isotopes. On the basis of calculations performed in order to determine the probabilities for delayed processes, it is shown that some of the delayed-fission probabilities calculated thus far were substantially overestimated. The application of these new results to calculating the r-process may change substantially both the r-process path and the yields of superheavy nuclei.

Energies of Gamov-Teller and Analog Resonances of Heavy and Superheavy Nuclei in a Quasiclassical Approach

The beta-decay strength function Sβ(E) is described within two approaches: numerical solution of equation of the theory of finite Fermi systems for the effective nuclear field and solution of these equations using the quasi-classical approximation. Calculations were carried out for the isotopes 71Ge and 127Xe. A comparison with experimental data showed their good accuracy. The resonance structure of the function Sβ(E) and the quenching-effect resulting from the effective charge of quasiparticles in the nucleus are discussed.

Giant Gamow-Teller resonance in neutron-rich nuclei

A powerful antineutrino source with a hard