Theoretical prediction of three-body cluster resonances in 11Li and 10He

With the core+n+n three-body cluster model, we investigated Li-11 and He-10. By using a Li-9-n interaction which reproduce the degeneracy of single particle s(1/2) - and p(1/2)-orbital states above the Li-9+n threshold, a low-lying excited resonance is predicted in Li-11 together with the ground state, and they are found to be partners in mixed configurations of (0p(1/2))(2) and (1s(1/2))(2). The observed three-body resonance in He-10 is considered to be the two valence neutrons mainly in the p-orbit, (0p(1/2))(2). In addition to a solution of the two valence neutrons in the p-orbit, we obtained a solution of the two valence neutrons mainly in the s-orbit, (1s(1/2))(2), as the ground state. Experimentally, such a state has not yet been observed. This newly predicted state of He-10 with the main component of (1s(1/2))(2) would corresponds to the ground state of Li-11 with a halo structure.