Search for two-quasiparticle wobbling modes in even-even isotopes of Ba, Nd, Xe, and Ce

The potential for two-quasiparticle wobbling modes in even-even nuclei is investigated through a combined approach of microscopic adiabatic and configuration-fixed constrained relativistic density functional theory (RDFT) and fully quantal particle rotor model (PRM) calculations for isotope chains $^{124--134}\mathrm{Ba}$, $^{122--138}\mathrm{Nd}$, $^{122--132}\mathrm{Xe}$, and $^{122--136}\mathrm{Ce}$. The RDFT calculations reveal the existence of multiple nuclear states characterized by optimal triaxial deformations and high-$j$ particle configurations, particularly the $\ensuremath{\pi}{h}_{11/2}^{2}$ and $\ensuremath{\nu}{h}_{11/2}^{2}$ configurations. These configurations enable the establishment of wobbling modes in these isotopes. A detailed examination of the resulting energy spectra, electromagnetic transition probabilities, and angular momentum geometry is further performed in the framework of PRM. The results indicate the potential for an extended region with wobbling modes in even-even nuclei in the mass region of $A\ensuremath{\approx}130$.