Relativistic Hartree plus Bogoliubov description of the deformed N=28 region -: art. no. 014310

Ground-state properties of neutron-rich N approximate to 28 nuclei are described in the framework of relativistic Hartree plus Bogoliubov (RH+B) theory. The model uses the NL3 effective interaction in the mean-field Lagrangian, and describes pairing correlations by the pairing part of the finite range Gogny interaction DIS. Two-neutron separation energies and ground-state quadrupole deformations that result from fully self-consistent RH+B solutions are compared with available experimental data. The model predicts a strong suppression of the spherical N = 28 shell gap for neutron-rich nuclei: the 1f7/2-->fp core breaking results in deformed ground states. Shape coexistence is expected for neutron-rich Si. S, and Ar isotopes.