Higher-order effects on the incompressibility of isospin asymmetric nuclear matter
- Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China)
- Cyclotron Institute and Physics Department, Texas A and M University, College Station, Texas 77843-3366 (United States)
- Department of Physics, Texas A and M University-Commerce, Commerce, Texas 75429-3011 (United States)
Analytical expressions for the saturation density of asymmetric nuclear matter as well as its binding energy and incompressibility at saturation density are given up to fourth order in the isospin asymmetry {delta}=({rho}{sub n}-{rho}{sub p})/{rho} using 11 characteristic parameters defined by the density derivatives of the binding energy per nucleon of symmetric nuclear matter, the symmetry energy E{sub sym} ({rho}), and the fourth-order symmetry energy E{sub sym,4}({rho}) at normal nuclear density {rho}{sub 0}. Using an isospin- and momentum-dependent modified Gogny interaction (MDI) and the Skyrme-Hartree-Fock (SHF) approach with 63 popular Skyrme interactions, we have systematically studied the isospin dependence of the saturation properties of asymmetric nuclear matter, particularly the incompressibility K{sub sat}({delta})=K{sub 0}+K{sub sat,2}{delta}{sup 2}+K{sub sat,4}{delta}{sup 4}+O({delta}{sup 6}) at saturation density. Our results show that the magnitude of the higher order K{sub sat,4} parameter is generally small compared to that of the K{sub sat,2} parameter. The latter essentially characterizes the isospin dependence of the incompressibility at saturation density and can be expressed as K{sub sat,2}=K{sub sym}-6L-(J{sub 0}/K{sub 0})L, where L and K{sub sym} represent, respectively, the slope and curvature parameters of the symmetry energy at {rho}{sub 0} and J{sub 0} is the third-order derivative parameter of symmetric nuclear matter at {rho}{sub 0}. Furthermore, we have constructed a phenomenological modified Skyrme-like (MSL) model that can reasonably describe the general properties of symmetric nuclear matter and the symmetry energy predicted by both the MDI model and the SHF approach. The results indicate that the higher order J{sub 0} contribution to K{sub sat,2} generally cannot be neglected. In addition, it is found that there exists a nicely linear correlation between K{sub sym} and L as well as between J{sub 0}/K{sub 0} and K{sub 0}. These correlations together with the empirical constraints on K{sub 0},L,E{sub sym} ({rho}{sub 0}), and the nucleon effective mass lead to an estimate of K{sub sat,2}=-370{+-}120 MeV.
- OSTI ID:
- 21289989
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 80, Issue 1; Other Information: DOI: 10.1103/PhysRevC.80.014322; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
Similar Records
Equation of state of neutron-rich matter in
NUCLEAR CONSTRAINTS ON PROPERTIES OF NEUTRON STAR CRUSTS