Robustness of the octupole collectivity in \({^{144}\textrm{Ba}}\) within the cranking covariant density functional theory in 3D lattice

The octupole deformation and collectivity in octupole double-magic nucleus \({^{144}\textrm{Ba}}\) $_{}^{144}\text{Ba}$ are investigated using the Cranking covariant density functional theory in a three-dimensional lattice space. The reduced B(E3) transition probability is implemented for the first time in semiclassical approximation based on the microscopically calculated electric octupole moments. The available data, including the I- \(\omega\) $\omega$ relation and electric transitional probabilities B(E2) and B(E3) are well reproduced. Furthermore, it is shown that the ground state of \({^{144}\textrm{Ba}}\) $_{}^{144}\text{Ba}$ exhibits axial octupole and quadrupole deformations that persist up to high spins ( \(I\approx 24\hbar\) $I\approx 24ħ$ ).