Isospin asymmetry in holographic baryonic matter

TL;DR

This paper investigates the phase structure of baryonic matter with isospin asymmetry using holographic models, revealing coexistence of pion condensation and isospin-asymmetric baryonic matter, and comparing confined and deconfined geometries.

Contribution

It introduces a holographic approach to study isospin asymmetric baryonic matter, including pion condensation, in both confined and deconfined geometries, advancing the understanding of dense QCD matter.

Findings

Pion condensation coexists with isospin-asymmetric baryonic matter at high chemical potentials.

Deconfined geometry provides better predictions for real-world QCD.

Phase diagrams mapped out for different chemical potentials.

Abstract

We study baryonic matter with isospin asymmetry, including fully dynamically its interplay with pion condensation. To this end, we employ the holographic Witten-Sakai-Sugimoto model and the so-called homogeneous ansatz for the gauge fields in the bulk to describe baryonic matter. Within the confined geometry and restricting ourselves to the chiral limit, we map out the phase structure in the presence of baryon and isospin chemical potentials, showing that for sufficiently large chemical potentials condensed pions and isospin-asymmetric baryonic matter coexist. We also present first results of the same approach in the deconfined geometry and demonstrate that this case, albeit technically more involved, is better suited for comparisons with and predictions for real-world QCD. Our study lays the ground for future improved holographic studies aiming towards a realistic description of charge neutral, beta-equilibrated matter in compact stars, and also for more refined comparisons with lattice studies at nonzero isospin chemical potential.