Particle-Vibration Coupling Effect on the Nuclear Shell Structure at Finite Temperature

In the present work, we investigate the shell evolution of neutron-rich even-even Ni isotopes (A = 68-78) with temperature in a beyond-mean-field framework, where a thermal relativistic mean-field model (RMF) is extended by including the coupling between nucleons and collective vibrations. The single-particle states are extracted by solving the temperature-dependent Dyson equation with the dynamical kernel of the particle-vibration coupling (PVC) origin on the basis of thermal RMF. The toy models in strongly truncated space are utilized to further investigate the sensitivity of the fragmentation pattern to the phonon frequencies, the mean-field level density, and the PVC strength.

Keywords: particle-vibration coupling, finite temperature, Matsubara Green's function