The properties of neutron star in the framework of relativistic Hartree–Fock model with unitary correlation operator method

The properties of neutron star are studied in the framework of relativistic Hartree–Fock (RHF) model with realistic nucleon–nucleon (NN) interactions, i.e., Bonn potentials. The strong repulsion of NN interaction at short range is properly removed by the unitary correlation operator method (UCOM). Meanwhile, the tensor correlation is neglected due to the very rich neutron environment in neutron star, where the total isospin of two nucleons can be approximately regarded as [Formula: see text]. The equations of state of neutron star matter are calculated in [Formula: see text] equilibrium and charge neutrality conditions. The properties of neutron star, such as mass, radius and tidal deformability, are obtained by solving the Tolman–Oppenheimer–Volkoff equation and tidal equation. The maximum masses of neutron from Bonn A, B, C potentials are around [Formula: see text]. The radius are [Formula: see text][Formula: see text]km at [Formula: see text], respectively. The corresponding tidal deformabilities are [Formula: see text]. All of these properties are satisfied with the recent observables from the astronomical and gravitational wave devices and are consistent with the results from the relativistic Brueckner–Hartree–Fock model.

SELF-CONSISTENT DESCRIPTION OF COLLECTIVE EXCITATIONS IN THE UNITARY CORRELATION OPERATOR METHOD

The fully self-consistent Random Phase Approximation (RPA) is constructed within the Unitary Correlation Operator Method (UCOM), which describes the dominant interaction-induced short-range central and tensor correlations by a unitary transformation. Based on the correlated Argonne V18 interaction, the RPA is employed in studies of multipole response in closed-shell nuclei across the nuclide chart. The UCOM-RPA results in a collective character of giant resonances, and it describes rather well the properties of isoscalar giant monopole resonances. However, the excitation energies of isovector giant dipole resonances and isoscalar giant quadrupole resonances are overestimated due to the missing long-range correlations and three-body contributions.