Drip-line nucleus of Z=59 nuclei in the relativistic mean-field theory

The possible neutron and proton drip-line nuclei and their corresponding properties of Pr isotope chain are studied in the framework of the relativistic mean-field (RMF) theory with non-linear meson self-interactions. The pairing effect is treated by BCS method and the isospin dependent pairing strengths have been adopted. The 'blocking' method is used to deal with the last unpaired nucleon and the axially symmetric deformation is assumed. The theoretical results show that the nucleus Pr-185 could be determined as the last stable nucleus with respect to the nucleon emission on the neutron rich side from various aspects, while on the proton rich side,it is difficult to determine the proton drip-line nucleus in present studies. The reason is that on the proton rich side the Fermi surface increases faster towards the continuum state than that on the neutron rich side, where the BCS method fails,and the coupling between bound and continuum states should be taken into account.