Analysis of the yrast bands with q-deformed moment of inertia

The rigid-rotor with a q-deformed moment of inertia is introduced to descri be the nuclear rotational spectra. With the representations of quantum alge bra, the normal deformed and superdeformed bands are naturally differentiat ed by softness. The yrast normal deformed bands in rare earth and actinium regions, as well as the yrast superdeformed bands in A-190 and 150 regions are investigated. The calculated results agree with experimental data quali tatively well, and the values of the parameters are physically reasonable. This indicates that the fixed deformation, the stretching effect and the ma ny body statistics effect are three possible dominant factors to govern nuc lear rotational bands.