Correlations in hot asymmetric nuclear matter

The single-particle spectral functions in asymmetric nuclear matter are computed using the ladder approximation within the theory of finite temperature Green's functions. The internal energy and the momentum distributions of protons and neutrons are studied as a function of the density and the asymmetry of the system. The proton states are more strongly depleted when the asymmetry increases whereas the occupation of the neutron states is enhanced compared to the symmetric case. The self-consistent Green's function approach leads to slightly smaller energies compared to the Brueckner-Hartree-Fock approach. This effect increases with density and thereby modifies the saturation density and leads to smaller symmetry energies.

Figure 1

Dependence of E/A on ${\alpha }^2$ computed in the SCGF approach (full lines) and in the BHF approach (dashed lines) at two densities, $\rho =0.16{\text{fm}}^{-3}$ (black lines) and $\rho =0.32{\text{fm}}^{-3}$ (red lines).

Figure 2

Dependence of neutron (upper curves) and proton (lower curves) chemical potentials μ on the asymmetry α calculated in the SCGF approach (solid lines) and in the BHF approach (dashed curves) at two given densities, $\rho =0.16{\text{fm}}^{-3}$ (black lines) and $\rho =0.32{\text{fm}}^{-3}$ (red lines).

Figure 3

$k=0$ MeV proton spectral function for different proton fractions. The calculations were performed at $\rho =0.16{\text{fm}}^{-3}\mathrm{and}T=5$ MeV.

Figure 4

$k=0$ MeV neutron spectral function for different proton fractions. The calculations were performed at $\rho =0.16{\text{fm}}^{-3}$ and $T=5$ MeV.

Figure 5

Dependence of the $k=0$ MeV on-shell width $\Gamma (0)$ on the proton fraction for neutrons (full lines) and protons (dashed lines) at two given densities, $\rho =0.16{\text{fm}}^{-3}$ (black lines) and $\rho =0.32{\text{fm}}^{-3}$ (red lines).

Figure 6

Dependence of the $n(0)$ on the proton fraction for neutrons (full lines) and protons (dashed lines) at two given densities, $\rho =0.16{\text{fm}}^{-3}$ (black lines) and $\rho =0.32{\text{fm}}^{-3}$ (red lines).

Figure 7

Momentum distributions for neutrons and protons for the SCGF approach (full lines) and the BHF approach (dashed lines) at a density $\rho =0.16{\text{fm}}^{-3}$ and asymmetry $\alpha =0.2$.