THE BOUNDARY CONDITION MODEL APPROACH TO BORROMEAN NUCLEI

Abstract

Three-body systems are studied in the framework of the Boundary Condition Model, in which the relevant interactions are expressed in terms of the scattering lengths of the two-body subsystems. We demonstrate explicitly the role of resonant states in the two-body subsystems and of multiple scattering between the constituents in producing a weakly bound three-body system, i.e. a Borromean nucleus. We obtain qualitative relations between the spatial extension of the three-body bound state, its energy, and the scattering lengths in the subsystems. The results are compared with experimental data for the Borromean nucleus 11 Li and 14 Be .