Ground State Properties of New Element Z=113 and Its Alpha Decay Chain

We investigate the ground state properties of the new element ²⁷⁸113 and of the α-decay chain with different models, where the new element Z=113 has been produced at RIKEN in Japan by cold-fusion reaction Morita et al. J. Phys. Soc. Jpn. 73(2004)2593. The experimental decay energies are reproduced by the deformed relativistic mean-field model, by the Skyrme--Hartree--Fock (SHF) model, and by the macroscopic-microscopic model. Theoretical half-lives also reasonably agree with the data. Calculations further show that prolate deformation is important for the ground states of the nuclei in the α-decay chain of ²⁷⁸113. The common points and differences among different models are compared and discussed.