Octupole deformation in the ground states of even-even Z ∼ 96, N ∼ 196 actinides and superheavy nuclei

A systematic search for axial octupole deformation in the actinides and superheavy nuclei with proton numbers Z = 88-126 and neutron numbers from the two-proton drip line up to N = 210 was performed in covariant density functional theory (DFT) using four state-of-the-art covariant energy density functionals representing different model classes. The nuclei in the Z similar to 96, N similar to 196 region of octupole deformation were investigated in detail and the systematic uncertainties in the description of their observables were quantified. A similar region of octupole deformation exists also in Skyrme DFT and microscopic+macroscopic approaches but it is centered at somewhat different particle numbers. Theoretical uncertainties in the predictions of the regions of octupole deformation increase on going to superheavy nuclei with Z similar to 120, N similar to 190. There are no octupole deformed nuclei for Z = 112-126 in covariant DFT calculations. This agrees with Skyrme DFT calculations, but disagrees with Gogny DFT and microscopic+ macroscopic calculations which predict an extended Z similar to 120, N similar to 190 region of octupole deformation.