Neutron matter properties from relativistic Brueckner-Hartree-Fock theory in the full Dirac space

A novel description of the strongly interacting pure neutron matter (PNM) was carried out by the relativistic Brueckner-Hartree-Fock (RBHF) theory in the full Dirac space with Bonn A potential. The scalar and vector components of the single-particle potentials are shown as functions of the momentum and the density, and are compared with the results obtained by the RBHF calculations in the Dirac space without negative-energy states. By benchmarking the binding energies of PNM to those predicted by several ab initio methods in the nonrelativistic framework with two- and three-body forces, we find our results are softer than those from the Brueckner-Hartree-Fock theory with the inclusion of three-body force, and in harmony with the ones obtained by the Monte Carlo method and many-body perturbation theory within uncertainties. In addition, the equation of state for neutron star matter is consistent with the constraints from multi-messenger astrophysical observation and heavy-ion collision experiments. The tidal deformabilities of a binary neutron star system are calculated and found consistent with the constraints from GW170817.

Automated summary

A novel description of strongly interacting pure neutron matter (PNM) is presented using the relativistic Brueckner-Hartree-Fock (RBHF) theory. The scalar and vector components of the single-particle potentials are compared with RBHF calculations without negative-energy states. The results show that the binding energies of PNM are softer than those predicted by the Brueckner-Hartree-Fock theory with three-body forces, and are consistent with Monte Carlo simulations and many-body perturbation theory within uncertainties. The equation of state for neutron star matter is also in agreement with astrophysical observations and heavy-ion collision experiments. Additionally, the tidal deformabilities of binary neutron star systems are calculated and found to be consistent with observational constraints from GW170817.