Theoretical description of E0, E1, E2 and M1 giant resonances

Self-consistent RPA+Skyrme BCS approach is used for the description of E0, E1, E2, M1 giant resonance positions and shapes. Comparison of the calculated E0 strength functions with experimental data demonstrates a known fact that it is not possible to describe experimental GMR in all isotopes with one parametrization of effective nucleon-nucleon interaction. It is also manifested how the coupling between E0 and E2 modes leads to the double-peak character of the GMR observed in deformed nuclei. A toroidal character of the nucleon flow in the E1 excitations in the pygmy E1 resonance energy region is shown. This leads to the new interpretation of the pygmy resonance (pygmy resonance is not connected only with a vibration of the neutron skin versus N=Z core). Comparison of the Skyrme RPA results with other theoretical approaches and with corresponding experimental data on the giant M1 resonance demonstrates a good RPA description of the scissor (orbital) part of the M1 resonance while for a good description of the spin-flip part of the M1 resonance it is necessary to go beyond the RPA. Calculated neutron and proton flows in the excited states of deformed nuclei with energies ∼3 MeV (scissor mode energies) are in agreement with the standard interpretation of the scissor M1 resonance (angular oscillation of the axially deformed proton system versus neutron system around an axis perpendicular to the nucleus symmetry axis). The shapes of the nucleon flow in other giant resonances are discussed as well. This document is composed of an abstract and the slides of the presentation. (author)