E2 selection rules of γ-rigid and γ-unstable rotors

Abstract

It has been known that the E2 selection rules are similar between the Davydov-Filippov rigid triaxial rotor model with γ = 30° and the O(6) limit of the interacting boson model (IBM). Using the O(6) limit of IBM, we investigate the relationship of the wavefunctions of O(6) and those of the Davydov-Filippov model. We introduce an intrinsic state with a fixed γ-value and construct its intrinsic excitation. It was shown by Ginocchio and Kirson that the O(6) wavefunctions can be expressed using the intrinsic state by the integration with respect to the γ-value. A formula is given which expresses the O(6) wavefunctions as a superposition of the γ-fixed intrinsic state and its intrinsic excitation. A discrete symmetry of these intrinsic excitations has been found, and by using this symmetry, we analyze the close connection between the E2 selection rules of the Davydov-Filippov rotor model and the O(6) limit of IBM.