Core excitation in 12Be Original Research Article

Motivated by much recent discussion of the N=8 neutron shell closure, we review the theoretical description of 12Be within a three-body (n+n+10Be) model with core excitation. Agreement with recently deduced 〈11Be|12Be〉 spectroscopic factors requires a smaller deformation of the 10Be core in 12Be than in 11Be, with a reduced role for core excitation. Observables for the ground state and 2+, 1− and 0+2 excited states of 12Be are presented. Limitations and improvements of the model are discussed.