2026/07/21 by Lorenzo Bartolini, Sven Bjarke Gudnason, Jonas Mager +1
#hep-ph #hep-th
We construct a nuclear-matter equation of state (EOS) from holographic QCD in the Witten-Sakai-Sugimoto (WSS) model, going beyond the homogeneous ansatz by building dense baryonic matter more directly from the solitonic description of holographic baryons. Employing the two-baryon interaction potential obtained from the linearized soliton tails sourced in the curved background by point-like (core) instantons, we assemble an infinite face-centered cubic (FCC) crystal with nearest neighbors in the most attractive channel as an approximation to the quantum liquid of baryons and compute the energy density E(nB), the chemical potential μB, and the pressure P. We calibrate the symmetric-matter EOS by fixing the 't Hooft coupling λ and the WSS scale M\rm KK to saturation-density and onset-chemical-potential properties, and by including a quark-mass term to reproduce the physical pion mass mπ=135 MeV. This fit turns out to remain reasonably close to the parameters required by the vacuum meson sector, while their modification is consistent with Brown-Rho scaling in a dense medium, and the incompressibility at saturation is of the correct order of magnitude, both in clear contrast to the homogeneous approximation. We then extend to beta-equilibrated matter, using phenomenological input for the symmetry energy, and obtain hybrid EOS and neutron-star observables that are compatible with the NICER constraints.