Effects of collective modes on shell structure of 10Be and 24O core Original Research Article

We study the effects of collective modes on shell structure in nuclei near the neutron drip line close to 10Be and 24O. Energy shifts in single-particle energies are evaluated by a particle–vibration coupling model. In the case of the 10Be core, the coupling to 2+ states is found to reduce the shell gap between 2s1/2 and 1p1/2 states. In the case of the 24O core, the couplings to 3− and 2+ states lead to a large energy gap between 2s1/2 and 1d3/2 states, in agreement with a recent experimental evidence of a new magic number at N=16 near the neutron drip line. In particular, the 3− vibrations are found to play a crucial role to push down the energy of the 2s1/2 state.