Excitation spectra of exotic nuclei in a self-consistent phonon-coupling model

We explore giant resonance spectra and low-lying dipole strength in the Ni and Sn chains from proton-rich to very neutron-rich isotopes, relevant in astrophysical reaction chains. For the theoretical description we employ the random-phase approximation plus many-body effects through a phonon-coupling model with optimized selection of phonons. The nuclear force is based on the Skyrme-Hartree-Fock energy functional carried consistently through all steps of modeling. The main effect of phonon coupling is a broadening of the spectral distributions (collisional width). This broadening is particularly dramatic for low-lying dipole strength in very neutron-rich nuclei delivering there a qualitative change of the spectra.