Shell Structure of Even-even Nickel Isotopes at Finite Temperature

Herlik Wibowo^1*, Elena Litvinova^2,3

¹Institute of Physics, Academia Sinica, Taipei City, Taiwan
²Department of Physics, Western Michigan University, Kalamazoo, Michigan, USA
³National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan, USA

* Presenter:Herlik Wibowo, email:herlik@gate.sinica.edu.tw

In the present work, we study the shell evolution of neutron-rich even-even nuclei ^68-78Ni with temperature using Matsubara Green's function formalism. The single-particle spectra for ^68-78Ni isotopes at zero and finite temperature are obtained by solving the temperature-dependent Dyson equation, which contains static and dynamical kernels. The static kernel has its origin from a self-consistent mean field generated by the effective mesons at finite temperature. The dynamical kernel takes into account the coupling between nucleons and phonons, which is responsible for the fragmentation of the single-particle states. We utilize the toy models in strongly truncated space to investigate the sensitivity of the fragmentation pattern to the phonon frequencies, the mean-field level density, and the nucleon-phonon coupling strength.

Keywords: nuclear shell structure, Matsubara Green’s function, Dyson equation, particle-vibration coupling, finite temperature mean field