Three-body Force Effects on Critical Temperature of Hot Nuclear Matter

The finite temperature Brueckner-Hartree-Fock approach (FTBHF) has been extended by introducing a microscopic three-body force. The three-body force is constructed from the meson-exchange current method[1]. Within the extended FTBHF framework, the equation of state (EOS) of hot symmetric nuclear matter has been investigated and the critical temperature of the liquid-gas transition has been calculated. The obtained

Equation of State of Asymmetric Nuclear Matter at Finite Temperature with a Three-body Force

In the present work, the equation of state of hot asymmetric nuclear matter nas Been investigated in the framework of the finite temperature Brueckner-Hartree-Fock (FTBHF) approach with a microscopic three-body force (TBF). The temperature dependence and the isospin dependence of the single particle properties, such as the proton and neutron single-particle potentials and effective masses have been studied. It is shown that the TBF gives a repulsive contribution to the proton or neutron single particle potential. The energy per nucleon versus asymmetry parameter is found to fulfill a parabolic relation as in the zero temperature case[I]. This means that the symmetry energy at finite temperature Esym can be extracted from' the energy difference between pure neutron matter and symmetric matter. The calculated symmetry energy is plotted in Fig.1.

Proton Fraction in Neutron Star Matter and Three-Body Force Effects

The three-body force effects on the equation of state and its iso-spin dependence of asymmetric nuclear matter and on the proton fraction in neutron star matter have been investigated[1] within Brueckner Hartree-Fock (BHF) approach by using a microscopic three-body force. It is shown that, even in the presence of the three-body force, the empirical parabolic law of the energy per nucleon vs. isospin asymmetry β=(N-Z)/A is fulfilled in the whole asymmetry range 0 ≤β ≤1 and also up to high density. The three-body force provides a strong enhancement of symmetry energy at high density in agreement with relativistic approaches. Thecalculated proton fraction in β stable neutron star matter is given in Fig.l, where the thick solid line is the BHF prediction using AV18+TBF, while the dotted one is the BHF result using AVis. The thin solid line is the prediction of the Dirac-Brueckner approach taken from Ref.[2]. The results extracted according to the phenomenological paramete rizations of the symmetry energy suggested in Ref.[3] are also plotted. It is seen

Three—Body Force Effects on EOS of Asymmetric Nuclear Matter and Proton Fraction in Neutron Star Matter

The three-body force effects on the equation of state and its iso-spin dependence of asymmetric nuclear matter and on the proton fraction in neutron star matter have been investigated within Brueckner-Hartree-Fock approach by using a microscopic three-body force. It is shown that, even in the presence of the three-body force, the empirical parabolic law of the energy per nucleon vs. isospin asymmetry is fulfilled in the whole asymmetry range and also up to high density. The three-body force provides a strong enhancement of symmetry energy at high density in agreement with relativistic approaches. It also shows that the three-body force leads to a much more rapid increasing of symmetry energy with density in relatively high density region and to a much lower threshold density for the direct URCA process to occur in a neutron star as compared to the predictions adopting only pure two-body force.