Nuclear Equation of State and Single-nucleon Potential from Gogny-like Energy Density Functionals Encapsulating Effects of Nucleon-nucleon Short-range Correlations

TL;DR

This paper develops a Gogny-like energy density functional incorporating nucleon-nucleon short-range correlations to better understand their effects on the equation of state and properties of dense neutron-rich matter, relevant for neutron stars.

Contribution

It introduces an analytical framework for including SRC-induced high momentum tails in energy density functionals, advancing the modeling of dense asymmetric nuclear matter.

Findings

Derived analytical expressions for the EOS components at saturation density.

Analyzed the impact of SRC/HMT on the symmetry energy and nucleon effective mass.

Explored consequences of SRC/HMT effects on neutron star properties.

Abstract

Nucleon-nucleon short-range correlations (SRCs) induce a high momentum tail (HMT) in the single-nucleon momentum distribution function $n_{\v{k}}^J(\rho,\delta)$ in cold neutron-rich matter. While there are clear experimental evidences that the SRC/HMT effects are different for neutrons and protons and their strengths depend strongly on the isospin asymmetry of finite nuclei mostly based on electron-nucleus scattering experiments, much less is known experimentally about the SRC/HMT effects in the dense neutron-rich matter. To facilitate further explorations of SRC/HMT effects in dense neutron-rich matter especially with heavy-ion reactions involving high-energy radioactive beams as well as multimessenger observations of neutron stars and their mergers, by incorporating the SRC-induced HMT in $n_{\v{k}}^J(\rho,\delta)$ into a Gogny-like energy density functional we study SRC/HMT effects on the equation of state (EOS) especially its symmetry energy term and single-nucleon potential in the dense asymmetric nucleonic matter (ANM). Using a parametrization as a surrogate for the momentum-dependent kernel in the Gogny-like energy density functional (EDF) we derive analytical expressions for all components of the ANM EOS and their characteristics (e.g., magnitude, slope and curvature as well as nucleon effective mass) at saturation density $\rho_0$ as well as the momentum-dependent single-nucleon optical potential in neutron-rich matter using parameters characterizing nuclear interactions as well as the size, shape and isospin dependence of the HMT at $\rho_0$. Some consequences of the SRC/HMT effects on properties of neutron stars are also studied.