Dense Hadronic Matter in Holographic QCD

TL;DR

This paper develops a holographic approach to study dense hadronic matter using the Sakai-Sugimoto model, revealing how density affects meson properties and the onset of matter freezing at high density.

Contribution

It introduces a method to analyze finite density hadronic matter holographically, demonstrating vector dominance and meson behavior at large densities within the Sakai-Sugimoto model.

Findings

Energy density saturates at high density, indicating matter freezing.

Pion velocity decreases to zero at high density.

The rho-pi-pi coupling vanishes at the freezing point.

Abstract

We provide a method to study hadronic matter at finite density in the context of the Sakai-Sugimoto model. We introduce the baryon chemical potential through the external $U(1)_v$ in the induced (DBI plus CS) action on the D8-probe-brane, where baryons are skyrmions. Vector dominance is manifest at finite density. We derive the baryon density effect on the energy density, the dispersion relations of pion and vector mesons at large $N_c$. The energy density asymptotes to a constant at large density suggesting that dense matter at large $N_c$ freezes, with the pion velocity dropping to zero. Holographic dense matter enforces exactly the tenets of vector dominance, and screens efficiently vector mesons. At the freezing point the $\rho-\pi\pi$ coupling vanishes with a finite rho mass of about 20% its vacuum value.