Towards holographic color superconductivity in QCD

TL;DR

This paper extends a holographic QCD model to include quark pairing, revealing a phase diagram with a second-order transition and a critical temperature around 30 MeV, highlighting the competition between homogeneous and modulated phases.

Contribution

The study introduces a charged scalar sector into the holographic V-QCD model to simulate quark pairing, unveiling new phase transition features and critical temperatures.

Findings

Identifies a second-order transition between paired and unpaired quark matter.

Critical temperature for pairing reaches approximately 30 MeV.

Homogeneous pairing growth rate is subdominant to modulated phases.

Abstract

We extend the holographic V-QCD model by introducing a charged scalar field sector to represent the condensation of paired quark matter in the deconfined phase. By incorporating this new sector into the previously established framework for nuclear and quark matter, we obtain a phase diagram that, in addition to the first-order deconfinement transition and its critical end-point, also features a second-order transition between paired and unpaired quark matter. The critical temperature for quark pairing exhibits only a mild dependence on the chemical potential and can reach values as high as $T_\mathrm{crit} \approx 30~\rm MeV$. Comparison of the growth rate for the formation of homogeneous paired phases to the growth rate of previously discovered modulated phases suggests that the former is subdominant to the latter.