Semiclassical description of wobbling and chiral modes in triaxial nuclei

Abstract

Abstract A time-dependent variational principle with an angular momentum coherent state as a variational state, is used to describe the dynamics associated to a triaxial rotor Hamiltonian with rigidly aligned high-j quasiparticles. Solving the variational principle within a stereographic parametrization of the coherent state, one obtains a classical energy function and a set of canonical equations of motion expressed in terms of the azimuth angle and a canonical conjugate coordinate represented by the third projection of the total angular momentum. The system’s rotational dynamics is investigated through the evolution on total angular momentum of the canonical variables as well as spherical angles corresponding to minima of the constant energy surface. The unique minimum energy conditions are spin-dependent and define phases with specific dynamic behaviour. The transition between phases is investigated for a single and two aligned quasiparticle spins. The discrete energy levels and corresponding wave-functions are obtained through a quantization procedure applied to the classical energy function. The formalism is used for numerical applications to 135Pr and 134Pr nuclei.