Beyond the core + n + n model for the neutron halo nucleus 11Li Original Research Article

A new model beyond the core + n + n model is discussed for two-neutron halo nucleus 11Li. In this model, pairing correlations among two halo neutrons and p-orbital neutrons in the 9Li core are taken into account as an important ingredient of the exotic binding mechanism. The 10L=9Li+n system, which is a subsystem of 9Li+n+n, is studied, and it is shown that the Pauli-blocking effect of pairing correlations of the 9Li-core cluster due to a View the MathML source neutron brings about the degeneracy of the single particle energies of View the MathML source and View the MathML source orbitals. For 11Li, three-body coupled-channel calculations are performed, and it is shown that the results explain observed exotic properties of very small separation energy S2n, large matter radius and large amplitude of the s-orbital configuration.