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Theoretical description of nuclear collective excitations

Nuclear Theory 2020-06-02 v4

Abstract

Density functional theory is a preferred microscopic method for calculation of nuclear properties over the whole nuclear chart. Besides ground-state properties, which are calculated by Hartree-Fock theory, nuclear excitations can be described by means of Random Phase Approximation (RPA). The main objective of the present work is to give Skyrme RPA formalism for spherically symmetric nuclei, using the techniques of angular-momentum coupling. Various auxiliary topics, such as Hartree-Fock theory, Coulomb integral, center-of-mass corrections and pairing, are treated as well. RPA method is derived also for axially deformed nuclei. The derived formulae are then implemented in the computer code and utilized for calculation of some physical results. After thorough investigation of the precision aspects of the calculation, the following topics are treated as examples: toroidal nature of the low-energy (pygmy) part of the E1 resonance, giant resonances of various multipolarities in deformed nucleus Sm-154, and magnetic dipole (M1) transitions in deformed Cr-50. Keywords: Random Phase Approximation, Skyrme functional, giant resonances in nuclei, reduced matrix elements I thank Jiri Mares and F. Knapp for their comments, which were taken into account in the first revision.

Keywords

Cite

@article{arxiv.1603.04383,
  title  = {Theoretical description of nuclear collective excitations},
  author = {Anton Repko},
  journal= {arXiv preprint arXiv:1603.04383},
  year   = {2020}
}

Comments

PhD thesis (Charles University in Prague), v4: corrected some misprints; updated spherical HF+RPA program: numerical optimizations, added spurious projection, (e,e') formfactors and effective current