Nuclear Shell Structure and Dynamical Nucleon Effective Mass in a Finite Temperature Relativistic Framework

Herlik Wibowo^1*, Elena Litvinova^2,3,4

¹Institute of Physics, Academia Sinica, Nangang District, Taipei City, Taiwan
²Department of Physics, Western Michigan University, Kalamazoo, Michigan, USA
³National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan, USA
⁴GANIL, CEA/DRF-CNRS/IN2P3, F-14076 Caen, France

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

We study the temperature evolution of nuclear shell structure and dynamical nucleon effective mass in medium-mass hot nuclei using the Matsubara Green's function technique. We model a hot nucleus as a system of Dirac nucleons moving in a self-consistent mean field generated by the effective mesons at finite temperature. We formulate the finite-temperature Dyson equation, which consists of the static and energy-dependent self-energies. The static self-energy originates from the thermal mean field, whereas the coupling between nucleons and phonons induces the energy-dependent self-energy. We solve the finite-temperature Dyson equation in the basis of Dirac spinors and investigate the fragmentation of the single-particle states and its temperature evolution for Nickel isotopes: ⁵⁶Ni, ⁶⁸Ni, and ⁷⁸Ni. From the energy-dependent self-energy, we extract the dynamical nucleon effective mass at various temperatures.

Keywords: nucleon effective mass, nuclear shell structure, Matsubara Green's function, Dyson equation, finite temperature mean field