Registration Number
0217U000604,
0112U004425
, R & D reports
Title
Studies of collective motion in atomic nuclei, nuclear decay and nuclear collisions near the barrier in the framework of semiclassical approximation.
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Head
Denisov Vitaly,
Registration Date
15-02-2017
Organization
Scientific Center "Institute for Nuclear Research" of National Academy of Sciences of Ukraine
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This stage is devoted to the research of collective pair excitations in heavy superfluid nuclei in the framework of semiclassic approach which grounds on the time dependent theory of Hartree-Fock-Bogoliubov. Analytical expression is got for the response function of anomalous density of superfluid fermi-sistem on the external field which causes a change of real part of the pair field (energy gap). It is found that a response has resonance in area of the doubled energy gap, which uncovers monopole pair vibrations in heavy superfluid nuclei. Using the semiclassic response function of anomalous nucleon density influence of pairing on kinetic properties of slow collective motion in heavy superfluid nuclei was considered. Analytical expressions were got for the coefficient of stiffness and mass parameter, relates to the monopole pair vibrations in a low frequency border. Isoscalar dipole modes in heavy kernels were examined within the framework of small vibration kinetic model in the finite fermi-system limited by the free surface. Analytical expression is got for the isoscalar response function of second order dipole moment taking into account remaining nucleon interaction (isoscalar in the first order, dipole response is the response of the system centre-of-mass). Including the residue interaction changes the compressibility of the fermi-system, and that is influences on isoscalar dipole modes. For the estimation of the residue interaction effects separable dipole-dipole type interaction was used. The parameter of interaction force gets out using the properties of monopole nodes of compression (giant monopole resonance), obtained in this kinetic model. A power function, calculated taking into account remaining interaction, has a double-resonance structure which appears also in a zero approach (without including of remaining interaction). The accounting of the remaining interaction leads to the displacement of resonances to the area of a lower frequencies and improves a agreement with experimental data for low-energy and high-energy isoscalar dipole modes in heavy nuclei.
Product Description
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Абросімов Валерій Іванович
Давидовська Оксана Іванівна
Денисов Віталій Юрійович
Левон Олександр Іванович
Нестеров Василь Олександрович
Пилипенко Микола Олександрович
Худенко Олександра Олександрівна
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2020-04-02
