Radii of the bound states in N-16 from the asymptotic normalization coefficients

The asymptotic normalization coefficients (ANCs) of the virtual decay N-16 -> N-15 + n are extracted from the N-15(Li-7, Li-6)N-16 reaction populating the ground and first three excited states in N-16. The root-mean-square (rms) radii of the valence neutron in these four low-lying N-16 states are then derived by using the ANCs. The probabilities of the valence neutron staying out of the core potentials are found to be 31% +/- 8%, 58% +/- 12%, 32% +/- 8%, and 60% +/- 12%. The present results support the conclusion that a one-neutron halo may be formed in the N-16 first and third excited states, while the ground and second excited states do not have a one-neutron halo structure. However, the core excitation effect has a strong influence on the one-neutron halo structure of the ground and first excited states in N-16.