Particle-vibration coupling and shell structure of exotic nuclei

We discuss the effects of particle-vibration coupling on the shell structure of nuclei near the neutron drip line by choosing, as examples, 10Be and 24O cores. In particular, we calculate the energy shifts of single-particle neutron states induced by the interaction with collective modes. In the case of the 10Be core, the coupling to 2+ states is responsible, within our model, of narrowing the N = 8 shell gap. On the other hand, in the case of the 24O core, the couplings to 3− and 2+ states lead to a large energy gap between the 2s1/2 and 1d3/2 states: this is in agreement with the experimental evidence of a new N = 16 magic number near the neutron drip line, discussed during this conference. For comparison, results for the stable 16O core, which are in overall agreement with the known data, are presented.