Study On The Rigidly-triaxial Critical Point Symmetry

In this work,the rigidly-triaxial critical point symmetry(CPS)named T(4)has been systematically studied.With the standard CPS technique,the analytic expressions of energy values,wave functions and E2 transitional rates of the T(4)CPS have been derived.Through comparing the low-lying structures in between the T(4)model and the interacting boson model,the dynamical trajectory of the T(4)model as a function of ? has been worked out,which indicates that the T(4)model can be reasonably applied to describe the critical point structures of different types of shape phase transitions in nuclear phase diagram as well as their evolutions with triaxial deformations.Moreover,the model validity of T(4)in describing the structural evolutions in critical nuclei with triaxial deformations has been further checked by fitting the experimental data related to typically critical nuclei in experiments.In addition,the T(4)CPS in its axially-symmetric limit has been extended from even-even nuclear system to odd-A nuclear system within the strong-coupling scheme,and the validity of such a extension has been further checked through analyzing the model validities of the CPS in both the even and odd cases in describing the rotational band structures of some transitional nuclei.