Hot nuclear matter equation of state with a three-body force

Abstract

The finite temperature Brueckner-Hartree-Fock approach is extended by introducing a microscopic three-body force. In the framework of the extended model, the equation of state of hot asymmetric nuclear matter and its isospin dependence have been investigated. The critical temperature of liquid-gas phase transition for symmetric nuclear matter has been calculated and compared with other predictions. It turns out that the three-body force gives a repulsive contribution to the equation of state which is stronger at higher density and as a consequence reduces the critical temperature of liquid-gas phase transition. The calculated energy per nucleon of hot asymmetric nuclear matter is shown to satisfy a simple quadratic dependence on asymmetric parameter β as in the zero-temperature case. The symmetry energy and its density dependence have been obtained and discussed. Our results show that the three-body force affects strongly the high-density behavior of the symmetry energy and makes the symmetry energy more sensitive to the variation of temperature. The temperature dependence and the isospin dependence of other physical quantities, such as the proton and neutron single particle potentials and effective masses are also studied. Due to the additional repulsion produced by the three-body force contribution, the proton and neutron single particle potentials are correspondingly enhanced as similar to the zerotemperature case.

Liquid-gas phase transition in nuclear matter from realistic many-body approaches

“…The effects on the gas phase, if any, would probably be very small in the homogeneous case. In fact, previous evaluations of the three-body effects on the critical temperature obtained within the BHF approach seem to indicate that these are rather small, about 1-3 MeV [22,53]. Such a decrease is much smaller than the discrepancies observed here when changing the two-body interaction or the many-body method.…”

“…The SCGF and the BHF approaches with two-body NN interactions cannot reproduce the saturation properties of nuclear matter at zero temperature because of the lack of repulsive contributions, most probably those coming from three-body forces [22,53]. The region of interest for liquid-gas phase transition studies is, however, in the low-density regime (critical densities are typically 1 2 to 1 3 of ρ 0 ), and this density regime should not be strongly modified by the presence of three-body forces.…”

“…The region of interest for liquid-gas phase transition studies is, however, in the low-density regime (critical densities are typically 1 2 to 1 3 of ρ 0 ), and this density regime should not be strongly modified by the presence of three-body forces. Estimates of the importance of the threebody forces in the liquid-gas regime have been performed within the BHF approximation, indicating small modifications to the critical properties [22,53].…”

Novel technique to extract experimental symmetry free energy information for nuclear matter

“…where ρ = ρ p + ρ n , m = (N − Z)/A is the neutron-proton asymmetry and E(ρ, T, m = 0) is the EOS of symmetric nuclear matter [20,21]. As a general representation of the symmetry energy coefficient, the following definition has been considered…”

Three-nucleon interaction in heavy-ion collisions at intermediate energies

“…In nuclear matter, the 3N force plays a vital role in nuclear structure, nuclear reactions, and nuclear astrophysics. Examples are studies in ab initio calculations for light and magic nuclei [3,4], nuclear drip lines [5,6], properties of the nuclear equation of state [7][8][9], neutron skins [10] and neutron stars [11][12][13]. Deeper understanding of 3N forces will open up new insights not only in nuclear physics, but also in related areas, such as astrophysics.…”