Core excitation in one neutron halo systems

Coupled channel calculations are performed for one neutron halo nuclei using a rotational model for the core structure. A deformed Woods-Saxon potential is used for the neutron-core interaction, where the deformation parameter is estimated using the quadrupole moment of the core and the charge to mass deformation ratio given by shell model calculations.Mean square radii and B(E1) transitions from the first excited state to the ground state in 11Be are presented and good agreement with experiment is found. The same calculations were performed for 13C but the agreement with experiment was not as good. Phase shifts for low energy neutrons on 10Be and 12C are calculated and we determine positions and widths of resonances. Predictions for the continuum only partly agree with the experimental spectrum. We also calculate the B(E1) distribution of 11Be for transitions from the ground state to the continuum and these agree with recent Coulomb dissociation data. Following the controversy generated by the experimental results for the ground state in 10Li, we apply our method to investigate the structure of this nucleus. (orig.)