Collective Hamiltonian for wobbling modes

TL;DR

This paper develops a collective Hamiltonian approach to study wobbling modes in nuclei, providing more accurate energies and wave functions than previous models, and analyzing their behavior with rotational frequency.

Contribution

It introduces a systematic method using collective Hamiltonian with parameters from tilted axis cranking to analyze wobbling modes, improving upon harmonic and particle rotor models.

Findings

Wobbling energies are closer to particle rotor model results.

Wobbling frequency increases with rotational frequency in simple and longitudinal modes.

Wobbling frequency decreases in transverse modes.

Abstract

The simple, longitudinal, and transverse wobblers are systematically studied within the framework of collective Hamiltonian, where the collective potential and mass parameter included are obtained based on the tilted axis cranking approach. Solving the collective Hamiltonian by diagonalization, the energies and the wave functions of the wobbling states are obtained. The obtained results are compared with those by harmonic approximation formula and particle rotor model. The wobbling energies calculated by the collective Hamiltonian are closer to the exact solutions by particle rotor model than harmonic approximation formula. It is confirmed that the wobbling frequency increases with the rotational frequency in simple and longitudinal wobbling motions while decreases in transverse wobbling motion. These variation trends are related to the stiffness of the collective potential in the collective Hamiltonian.