Cluster model with core excitations. The 11Be example

Abstract

Bound states and low-lying resonances of the 11Be one-neutron halo nucleus have been calculated within a two-body cluster model with core excitation. The lowest 10Be core excited 2+ state was considered as a quadrupole vibration. Shallow potentials were applied for neutron-core interaction, preventing motion in Pauli forbidden orbits. A good description of available experimental data including dipole excitations of 11Be was obtained. For the bound 1/2− excited state the $$\left[ {p_{3/2} \otimes 2^ + } \right]_{1/2^ - }$$ wave-function component gives the dominant contribution to the structure, which differs from results obtained in cluster models with deep potentials.