Nature of Isoscalar Dipole Resonances in Heavy Nuclei

  • V. I. Abrosimov Institute for Nuclear Research, Nat. Acad. Sci. of Ukraine
  • O. I. Davydovska Institute for Nuclear Research, Nat. Acad. Sci. of Ukraine
Keywords: kinetic model, isoscalar dipole nuclear response, velocity field, vortex and compression modes

Abstract

The isoscalar dipole nuclear response reveals low- and high-energy resonances. The nature of isoscalar dipole resonances in heavy spherical nuclei is studied, by using a translation-invariant kinetic model of small oscillations of finite Fermi systems. Calculations of the velocity field at the centroid energy show a pure vortex character of the low-energy isoscalar dipole resonance in spherical nuclei and confirm the anisotropic compression character of the high-energy one. The evolution of the velocity field as a function of the excitation energy of the nucleus within the resonance width is studied. It is found that the low-energy isoscalar dipole resonance retains a vortex character, while with this collective excitation also involves a compression, as the energy increases. The high-energy resonance keeps the compression character with a change in the excitation energy within the resonance width, but the compression-expansion region of the velocity field related to this resonance shifts inside the nucleus.

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Published
2018-12-09
How to Cite
Abrosimov, V., & Davydovska, O. (2018). Nature of Isoscalar Dipole Resonances in Heavy Nuclei. Ukrainian Journal of Physics, 63(12), 1043. https://doi.org/10.15407/ujpe63.12.1043
Section
Fields and elementary particles