Collective Hamiltonian for chiral modes

TL;DR

This paper develops a collective Hamiltonian model to describe chiral rotation and vibration in a specific nuclear system, revealing how partner states evolve with cranking frequency and highlighting the role of vibrations at the onset of rotation.

Contribution

It introduces a novel collective Hamiltonian based on tilted axis cranking for modeling chiral modes in nuclei, integrating potential energy and mass parameters.

Findings

Partner states become more degenerate with increased cranking frequency.

Chiral vibrations are crucial for collective excitations at the start of rotation.

The model successfully describes the transition from vibration to rotation.

Abstract

A collective model is proposed to describe the chiral rotation and vibration and applied to a system with one $h_{11/2}$ proton particle and one $h_{11/2}$ neutron hole coupled to a triaxial rigid rotor. The collective Hamiltonian is constructed from the potential energy and mass parameter obtained in the tilted axis cranking approach. By diagonalizing the collective Hamiltonian with a box boundary condition, it is found that for the chiral rotation, the partner states become more degenerate with the increase of the cranking frequency, and for the chiral vibrations, their important roles for the collective excitation are revealed at the beginning of the chiral rotation region.