  By the very definition the triaxial deformation parameter $\gamma$ is related
to the expectation values of the K=0 and K=2 components of the intrinsic
quadrupole tensor operator. On the other hand, using the same symbol
"$\gamma$", various different parametrizations of triaxial deformation have
been employed, which are suitable for various types of the mean-field
potentials. It is pointed out that the values of various "$\gamma$" are quite
different for the same actual triaxial deformation, especially for the large
deformation; for example, the difference can be almost a factor two for the
case of the triaxial superdeformed bands recently observed in the Hf and Lu
nuclei. In our previous work, we have studied the wobbling band in Lu nuclei by
using the microscopic framework of the cranked Nilsson mean-field and the
random phase approximation, where the most serious problem is that the
calculated B(E2) value is about factor two smaller. It is shown that the origin
of this underestimation can be mainly attributed to the small triaxial
deformation; if is used the same triaxial deformation as in the analysis of the
particle-rotor model, the calculated B(E2) increases and gives correct
magnitude compared with the experimental data.
