Nuclear matter fourth-order symmetry energy in nonrelativistic mean-field models

作者：Pu, Jie; Zhang, Zhen; Chen, Lie-Wen^*

来源：PHYSICAL REVIEW C, 2017, 96(5): 054311.

DOI：10.1103/PhysRevC.96.054311

• HEAVY-ION COLLISIONS
• NEUTRON-RICH NUCLEI
• EQUATION-OF-STATE
• ISOSPIN PHYSICS
• MASS FORMULA
• FREE-PATH
• INCOMPRESSIBILITY
• SCATTERING
• DENSITIES
• DYNAMICS

Background: Nuclear matter fourth-order symmetry energy E-sym,E-4(rho) may significantly influence the properties of neutron stars such as the core-crust transition density and pressure as well as the proton fraction at high densities. The magnitude of E-sym,E-4(rho) is, however, largely uncertain. @@@ Purpose: Based on systematic analyses of several popular nonrelativistic energy density functionals with mean-field approximation, we estimate the value of the E-sym,E-4(rho) at nuclear normal density rho(0) and its density dependence, and explore the correlation between E-sym,E-4(rho(0)) and other macroscopic quantities of nuclear matter properties. @@@ Method: We use the empirical values of some nuclear macroscopic quantities to construct model parameter sets by the Monte Carlo method for four different energy density functionals with mean-field approximation, namely, the conventional Skyrme-Hartree-Fock (SHF) model, the extended Skyrme-Hartree-Fock (eSHF) model, the Gogny-Hartree-Fock (GHF) model, and the momentum-dependent interaction (MDI) model. With the constructed samples of parameter sets, we can estimate the density dependence of E-sym,E-4(rho) and analyze the correlation of E-sym,E-4(rho) with other macroscopic quantities. @@@ Results: The value of E-sym,E-4(rho(0)) is estimated to be 1.02 +/- 0.49 MeV for the SHF model, 1.02 +/- 0.50 MeV for the eSHF model, 0.70 +/- 0.60 MeV for the GHF model, and 0.74 +/- 0.63 MeV for the MDI model. Moreover, our results indicate that the density dependence of E-sym,E-4(rho) is model dependent, especially at higher densities. Furthermore, we find that the E-sym,E-4(rho(0)) ) has strong positive (negative) correlation with isoscalar (isovector) nucleon effective mass m*(s,0)(m*(v,0)) at rho(0). In particular, for the SHF and eSHF models, the E-sym,E-4(rho) is completely determined by the isoscalar and isovector nucleon effective masses m*(s)(rho) and m*(v)(rho), and the analytical expression is given. @@@ Conclusions: In the mean-field models, the magnitude of E-sym,E-4(rho(0)) is generally less than 2 MeV, and its density dependence depends on models, especially at higher densities. E-sym,E-4(rho(0)) is strongly correlated with m*(s,0) and m*(v,0)

• 出版日期2017-11-14
• 单位上海交通大学