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

摘要

We have studied properties and the shell structure of the superheavy elementsfrom Z = 102 to Z = 120 within the framework of relativistic mean field(RMF) theory. The region of study spans nuclides with neutron numbersN = 150-190. The Lagrangian model NL-SV 1 with the inclusion of thevector self-coupling of the co-meson has been employed in this work. We haveperformed RMF + BCS calculations for an axially deformed configurationof nuclei. The ground-state binding energies, single-particle properties andquadrupole deformation of nuclei have been obtained from the mean-fieldminimizations. Two-neutron separation energies, Qa values and a-decay half-life have been evaluated. It is shown that a large number of nuclides exhibit thephenomenon of shape coexistence over a significant region of the superheavyelements. Shape coexistence of a prolate and an oblate shape is prevalent innuclides far below N = 184, whilst nuclei in the vicinity of N = 184 tendto show a shape coexistence between a spherical and an oblate shape. Theshell structure and two-neutron separation energies obtained with RMF theoryreinforce the neutron number N = 184 as a major magic number. It is shownthat the neutron number N = 172 acts akin to a magic number in the deformedregion. It is suggested that the combination of Z = 120 and N = 172 has thepotential of being a doubly magic number in the superheavy region.