Time : 2021/06/17 (Thu.) 12:30
Place : online 

Abstract: 
The atomic nucleus is a many-body quantum system of strongly interacting nucleons
(protons and neutrons). Understanding the behavior of nuclear systems at finite
temperature remains a significant challenge in nuclear theory. The concept of nuclear
temperature is attributed to the long-lived hot nuclei (highly excited compound
nuclei) as intermediate states of such processes as neutron capture and heavy-ion
collisions. In astrophysical environments, such as neutron stars and supernovae,
finite temperature becomes an essential factor, which modifies the rates of various
nuclear reactions, from the radiative neutron capture to the weak processes.

In this talk, I will present an approach to solving a nuclear many-body problem at
finite temperature. In this approach, a hot nucleus is modeled as a system of Dirac
nucleons moving in a self-consistent mean field generated by the effective mesons at
finite temperature. In-medium correlations between nucleons are taken into account
using Matsubara Green's function formalism. The finite-temperature Dyson equation,
which contains the static and energy-dependent self-energies, is formulated and solved
in the basis of Dirac spinors. The static self-energy originates from the thermal mean
field, whereas the coupling between nucleons and phonons induces the energy-dependent
self-energy. Within this approach, I investigate the fragmentation of single-particle
states and its evolution with temperature for Nickel isotopes (68,70,72,74,76,78Ni).