Superheavy nuclei with the vector self-coupling of the ω-meson in relativistic mean-field theory

Abstract

We have studied properties and the shell structure of the superheavy elements from Z = 102 to Z = 120 within the framework of relativistic mean field (RMF) theory. The region of study spans nuclides with neutron numbers N = 150–190. The Lagrangian model NL-SV1 with the inclusion of the vector self-coupling of the ω-meson has been employed in this work. We have performed RMF + BCS calculations for an axially deformed configuration of nuclei. The ground-state binding energies, single-particle properties and quadrupole deformation of nuclei have been obtained from the mean-field minimizations. Two-neutron separation energies, Qα values and α-decay half-life have been evaluated. It is shown that a large number of nuclides exhibit the phenomenon of shape coexistence over a significant region of the superheavy elements. Shape coexistence of a prolate and an oblate shape is prevalent in nuclides far below N = 184, whilst nuclei in the vicinity of N = 184 tend to show a shape coexistence between a spherical and an oblate shape. The shell structure and two-neutron separation energies obtained with RMF theory reinforce the neutron number N = 184 as a major magic number. It is shown that the neutron number N = 172 acts akin to a magic number in the deformed region. It is suggested that the combination of Z = 120 and N = 172 has the potential of being a doubly magic number in the superheavy region.