English

Relativistic mean-field model with density- and isospin-density-dependent couplings

Nuclear Theory 2025-11-20 v1 High Energy Astrophysical Phenomena High Energy Physics - Phenomenology

Abstract

We present a new hadronic EoS with hyperons built within the relativistic mean-field (RMF) formalism with baryon-density- and isospin-density-dependent couplings. Motivated by microscopic calculations showing density- and isospin-asymmetry-dependence of self-energies, we implement a new form for the baryon-meson couplings. The parameters for the couplings are constrained by a Bayesian analysis, which anchors the model to nuclear saturation properties, chiral effective field theory (χ\chiEFT) predictions for pure neutron matter, heavy-ion collision data, and HALQCD-based hyperon potential calculations at 3-momentum k=0|\mathbf{k}|=0 in both isospin-symmetric and pure neutron matter. The resulting EoS satisfies neutron star mass-radius constraints from NICER and GW170817, providing another way to address the hyperon puzzle. The low-density part of the EoS is described via nuclear statistical equilibrium with modern mass tables (AME20/FRDM12, 8244 nuclei), providing a novel and complete general-purpose EoS for astrophysical simulations.

Keywords

Cite

@article{arxiv.2511.15646,
  title  = {Relativistic mean-field model with density- and isospin-density-dependent couplings},
  author = {Gabriel Frohaug and Konstantin Maslov and Veronica Dexheimer and Joaquin Grefa and Johannes Jahan and Claudia Ratti and Tulio E. Restrepo},
  journal= {arXiv preprint arXiv:2511.15646},
  year   = {2025}
}

Comments

23 pages, 10 figures