| The concept of wobbling motion in atomic nuclei was originally introduced by Bohr and Mottelson in the 1970s for triaxial even-even nuclei.Later,the first wobbling band was suggested in the odd-mass 163Lu nuclei in 2001.Thereafter,following the next two decades,more than ten examples of wobbling bands had been reported and so far,it is a hot topic in current nuclear structure.To develop the understanding of the picture for nuclear wobbling motion,the influence of moments of inertia on the wobbling motion has been discussed in even-even and odd-mass nuclei.The main discussion points include:1.Influence of moments of inertia on wobbling motion in even-even nucleiThe influence of triaxial deformation γ-dependent moments of inertia on the wobbling motion in even-even nuclei with no particle has been discussed based on the triaxial rotor model.The harmonic approximation gets well as γ approaches 30° for the properties of energy spectra and electric quadrupole transition probabilities.In addition,two types of angular momentum geometries for wobbling motion,stemming from different values of moments of inertia,are exhibited by azimuthal plots.It is found that the picture of ideal precession only appears when the moments of inertia of short axis equal to that of long axis.Recent data from a Coulomb excitation experiment of 110Ru are studied,and the 31+ and 22+ states might be suggested as the bandhead of the wobbling bands.2.Influence of moments of inertia on transverse wobbling mode in odd-mass nucleiThe reported transverse wobbling bands in odd-mass 163Lu and 105Pd have been reinvestigated by the triaxial particle rotor model.For the wobbling mode in triaxial strongly deformed bands of 163Lu,the calculated results could describe the experimental data well with the parameters of moment of inertia(MOI)which approximately in accordance with rigid model.It exhibits the steady transverse wobbling mode all the way up to high spin.For 105Pd,employing different parameter sets of MOI,several calculated results could be in good agreement with the experimental data,which show distinct modes of rotational excitation,respectively.These modes are sensitive to the ratio between the MOI at intermediate and short axis.With the increase of this ratio,a wobble about the short axis of the total angular momentum is gradually changed to a wobble about the intermediate axis.In addition,it is exhibited that precession and tunneling are two aspects of the quantum wobbling motion.The tunneling aspect dominates in the yrare states of both 163Lu and 105Pd. |
