Low-Energy Spectrum of One-Neutron Halo Nucleus 11 Be

We investigate the low-energy spectrum of the one-neutron halo nucleus 11Be using the complex scaled coupled channel method for a 10Be + n model, paying attention to the effects of the deformation of the 10Be-core and the Pauli principle between the core and a valence neutron. For positive parity states of 11Be, our calculation well reproduces the experimental results, but for negative parity states, not so well. With reducing the coupling between the core deformation and a valence neutron, the negative parity levels of the 11Be nucleus are much improved.