A Holographic Description of Colour Superconductivity

TL;DR

This paper proposes a holographic model to describe the QCD colour superconducting phase, focusing on the role of gapped gluons and four-fermion interactions near the chiral transition, providing insights into phase transitions and quark mass effects.

Contribution

It introduces a holographic framework for colour superconductivity that incorporates gapped gluons and four-fermion interactions, offering a new perspective on the phase diagram.

Findings

Holographic model captures the colour superconducting phase diagram.

Gapped gluons relate to the strength of four-fermion interactions.

Quark mass influences the transition between different superconducting phases.

Abstract

The difficulty of describing the gauge dependent bi-quark condensate in the QCD colour superconducting phase has made it hard to construct a holographic dual of the state. To side step this problem, we argue that near the chiral restoration transition in the temperature-chemical potential plane, the strongly coupled gluons are likely completely gapped so that the colour quantum numbers of the quarks can be thought of below that gap as global indices. A standard AdS-superconductor model can then be used to analyze the fermionic gap formation. We investigate the role of four-fermion interactions, which might be used to include the gapped QCD interactions, on the vacuum and metastable vacua of the model. It turns out to be easiest to simply relate the standard interaction of the holographic superconductor to the strength of the gapped gluons. The result is a holographic description of the QCD colour superconducting phase diagram. We take a first look at how quark mass enters and causes a transition between the colour flavour locked phase and the 2SC phase.