Abstract:
The recent progresses on the wobbling motion are briefly introduced. So far 17 wobbling candidates have been reported in odd-
A and even-even nuclei that spread over
A≈100, 130, 160 and 190 mass regions. The two-quasiparticle configuration wobbling in
130Ba and the wobbling motion in a triaxial rotor are taken as examples in this paper to show the wobbling motion in even-even nuclei. For the
130Ba, the wobbling are investigated based on the combination of the covariant density functional theory (CDFT) and the particle rotor model (PRM). The CDFT provides crucial information on the configuration and deformation parameters of observed bands, serving as input for PRM calculations. The corresponding experimental energy spectra and electromagnetic transition probabilities are reproduced. An analysis of the angular momentum geometry reveals the enhanced stability of transverse wobbling of a two-quasiparticle configuration compared to a single-quasiparticle one. For the triaxial rotor, the time evolution of wobbling motion is explored through the solution of Euler equations. This investigation yields valuable insights into the evolution of orientation angles (\phi and \theta ) and angular momentum components. Notably, the study reveals that low-energy states of a triaxial rotor predominantly exhibit wobbling motion around the intermediate axis. Moreover, an increase in excitation energy corresponds to a prolonged period of intermediate axis wobbling motion. Conversely, a contrasting trend is observed in the case of long axis wobbling, where an increase in excitation energy leads to a decrease in the wobbling period.