Self-consistent models for the collective excitation phenomena in exotic nuclei

摘要

Multipole excitation phenomena in exotic nuclei are investigated within the framework of the fully self-consistent Relativistic Quasi-particle Random-Phase Approximation (RQRPA) based on the Relativistic Hartree-Bogoliubov (RHB) model with density dependent meson-nucleon couplings, and finite-range Gogny interaction to account for the pairing correlations. The RHB+RQRPA study of nuclei towards the proton drip-line indicates the appearance of an exotic collective excitation mode: the proton pygmy dipole resonance, due to oscillations of loosely bound protons against the rest of nucleons. The continuum RPA using Skyrme interactions is employed in a study of doubly magic 48Ni, resulting in a rather broad distribution of the low-lying dipole strength, due to the coupling to the continuum.