Three-body model calculations for the ¹⁶C nucleus

We apply a three-body model consisting of two valence neutrons and the core nucleus ¹⁴C in order to investigate the ground state properties and electric quadrupole transition of the ¹⁶C 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 ¹⁵C. We also show that the present calculation accounts well for the longitudinal momentum distribution of the ¹⁵C fragment from the breakup of the ¹⁶C nucleus. We point out that the dominant (d_5/2)² configuration in the ground state of ¹⁶C plays a crucial role in these agreements.