Liquid-Gas Phase Transition In Thermal Nuclear Matter Within Covariant Density Functional Theory

Due to the behavior of van der Waals-like force of nucleon-nucleon interaction,the phenomena of liquid-gas phase transition similar to that in condensed matter physics may be occurred in sub-saturated thermal nuclear matter.The liquid-gas phase transition of thermal nuclear matter can be emerged in heavy-ion collision and neutron star,which has a very important effect on the physical processes related to the heavy-ion collision and neutron star.Based on this,we utilized the covariant density functional theory to systematically study the liquid-gas phase transition phenomena of thermal nuclear matter.The main content of this thesis includes two parts: firstly,the correlations of critical points and phase diagrams of liquid-gas phase transition in symmetric and asymmetric thermal nuclear matter are analyzed systemically;secondly,within the framework of covariant density functional theory,mainly based on the relativistic Hartree-Fock theory,the relationship between the equilibrium of nuclear dynamics and liquid-gas phase transition of thermal nuclear matter is discussed emphatically.Systematic study of properties of liquid-gas phase transition in thermal nuclear matter The phenomenon of liquid-gas phase transition in thermal nuclear matter is studied systematically with the covariant density functional theory,it is found that there exist the significant correlations between critical temperature and other critical parameters at the critical point of liquid-gas phase transition,these correlations can be utilized to constrain the critical temperature.In describing the properties of liquid-gas phase diagram,it is found that the phase coexistence area of liquid-gas phase diagram is directly correlated to the contribution of symmetry energy related part.Also,similar as the correlations of critical parameters,there exist the significant correlations between critical temperature and characteristic pressures of corresponding phase diagram of liquid-gas phase transition at isospin asymmetry case.These above correlations can help us to clarify the uncertainty of theoretical prediction to the properties of LG phase transition and to better understand the physics of liquid-gas phase transition.The equilibrium of nuclear dynamics and liquid-gas phase transition of thermal nuclear matter In the framework of covariant density functional theory,based on the relativistic Hartree-Fock approach with PKA1 functional,the effects of ?-tensor coupling on liquid-gas phase transition of thermal nuclear matter are discussed.When changing the coupling strength of ?-tensor and the density-dependent behavior of iso-scalar channels(nuclear in-medium effects),the critical temperature and the phase coexistence area of phase diagram of liquid-gas phase transition we obtained can be compared to the results of other CDF functionals.This is due to the change of equilibrium mechanism of nuclear dynamics when the coupling strength of ?-tensor is changed,which finally lead to the change of the critical temperature and phase diagram properties of liquid-gas phase transition of thermal nuclear matter.