α-decay properties of superheavy elements Z=113-125 in the relativistic mean-field theory with vector self-coupling of ω meson

We have investigated properties of α-decay chains of recently produced superheavy elements Z=115 and Z=113 using the new Lagrangian model NL-SV1 with inclusion of the vector self-coupling of the ω meson in the framework of relativistic mean-field theory. It is shown that the experimentally observed α-decay energies and half-lives are reproduced well by this Lagrangian model. Further calculations for the heavier elements with Z=117-125 show that these nuclei are superdeformed with a prolate shape in the ground state. A superdeformed shell closure at Z=118 lends an additional binding and an extra stability to nuclei in this region. Consequently, it is predicted that the corresponding Qα values provide α-decay half-lives for heavier superheavy nuclei within experimentally feasible conditions. The results are compared with those of macroscopic-microscopic approaches. A perspective of the difference in shell effects among various approaches is presented and its consequences for superheavy nuclei are discussed