Exploration of Unbound States by Analytical Continuation in the Coupling Constant Method Within Relativistic Mean Field Theory

For the first time, the analytical continuation in the coupling constant method has been combined with the relativistic mean field theory to study the unbound states in spherical nuclei. The 1d_3/2 neutron state in ¹⁶O and the 2d_5/2 and 1g_9/2 neutron states in ⁴⁸Ca are taken as examples. The calculated energies and widths are compared with available data.