Shape coexistence in even-even superheavy nuclei

The structures of the even-even superheavy nuclei with proton number Z = 100-114 are systematically investigated using self-consistent relativistic mean-field theory. The calculated binding energies are in good agreement with all available experimental data. The experimental alpha decay energies and lifetimes of the newly discovered superheavy nuclei are also reasonably reproduced by the model. Large scale calculations with a quadrupole moment constraint clearly show the variation of energy with the quadrupole deformation parameter. It reliably demonstrates that there is shape coexistence in superheavy nuclei. In some cases the configuration with superdeformation may be the ground state of superheavy nuclei near Z = 114 and N = 174.