Ground-state properties of closed-shell nucleus 56Ni with realistic nucleon-nucleon interactions

We have calculated the ground-state energy of the doubly magic nucleus 56Ni within the framework of the Green's function using the CD-Bonn and N3LO nucleon-nucleon potentials. For the sake of comparison, the same calculations are performed using the Brueckner-Hartree-Fock approximation. Both the continuous and conventional choices of single particle energies are used. Additional binding energy is obtained from the inclusion of the hole-hole scattering term within the framework of the Green function approach. In this study, comparison of the calculated ground-state energies, obtained by using the Brueckner-Hartree-Fock approach using continuous choice and different nucleon-nucleon potentials, with the experimental value is accomplished. The results show good agreement between the calculated values and the experimental one for the 56Ni nucleus. The sensitivity of our results to the choice of the model space is examined.