3D relativistic Hartree-Bogoliubov model with a separable pairing interaction: Triaxial ground-state shapes

Potential-energy surfaces and pairing energy maps of nuclei with triaxial shapes are studied in the framework of the relativistic Hartree-Bogoliubov (RHB) model. The recently introduced separable pairing force, adjusted in nuclear matter to the pairing gap of the Gogny force, is employed in the pairing channel of the three-dimensional RHB model for triaxial shapes, and the density-dependent meson-exchange effective interaction (DD-ME2) is used in the particle-hole channel. Even-$A$ Pt isotopes with triaxial ground-state shapes and Sm nuclei with $\ensuremath{\gamma}$-soft potential-energy surfaces are analyzed.