Three-body model calculations for the C16 nucleus

We apply a three-body model consisting of two valence neutrons and the core nucleus C14 in order to investigate the ground state properties and electric quadrupole transition of the C16 nucleus. The discretized continuum spectrum within a large box is taken into account by using a single-particle basis obtained from a Woods-Saxon potential. The calculated B(E2) value from the first 2+ state to the ground state shows good agreement with the observed data with the core polarization charge which reproduces the experimental B(E2) value for C15. We also show that the present calculation accounts well for the longitudinal momentum distribution of the C15 fragment from the breakup of the C16 nucleus. We point out that the dominant (d5/2)2 configuration in the ground state of C16 plays a crucial role in these agreements.