Relativistic Hartree–Fock chiral Lagrangians with confinement, nucleon finite size and short-range effects

• Published in: The European physical journal. A, Hadrons and nuclei Vol. 59; no. 8
• Main Authors: Chamseddine, Mohamad, Margueron, Jérôme, Chanfray, Guy, Hansen, Hubert, Somasundaram, Rahul
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 02-08-2023; Springer Nature
• Subjects: ATOMIC AND MOLECULAR PHYSICS; Atomic, Nuclear and Particle Physics; Hadrons; Heavy Ions; Nuclear Fusion; Nuclear Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Regular Article - Theoretical Physics
• ISSN: 1434-601X; 1434-601X
• DOI: 10.1140/epja/s10050-023-01089-2

A relativistic Hartree–Fock Lagrangian including a chiral potential and nucleon polarisation is investigated in hopes of providing a better description of dense nuclear matter. We fully consider the contribution of the exchange Fock term to the energy and the self-energies, and in addition we investigate the nucleon’s compositeness and finite size effects (confinement and form factors) and short range correlations modeled by a Jastrow ansatz. These effects are added step by step, such that their impact on the dense matter properties can be analysed in details. The parameters of the model are adjusted to reproduce fundamental properties related to the QCD theory at low energy, such as the chiral symmetry breaking, nucleon’s quark substructure and Lattice-QCD predictions, as well as two empirical properties at saturation: the binding energy and the density. All other empirical parameters, e.g., symmetry energy and its slope, incompressibility modulus, effective mass, as well as spin–isospin Landau–Midgal parameter are predictions of the models and can be used to evaluate the gain of the different approximation schemes in describing nuclear properties. Bayesian statistics is employed in order to propagate parameter uncertainties into predictions for the nuclear matter properties. We show that the splitting of the effective Landau mass is largely influenced by the value of the
ρ
T
coupling, and we show that the fit to the symmetry energy, which induces an increase of the coupling constant
g
ρ
by about 20–25% compared to the case where it is fixed by the quark model, provides a very good EoS compatible with the present nuclear physics knowledge.