Effective theory of color superconductivity

TL;DR

This paper reviews an effective theory of QCD at high baryon density, highlighting its properties and applications to gapless superconductors, including recent solutions to magnetic instability issues.

Contribution

It introduces a high-density effective theory of QCD that maintains gauge invariance and reparametrization invariance, enabling lattice simulations and addressing superconductivity instabilities.

Findings

The effective theory preserves gauge invariance and has a positive measure.

It facilitates lattice simulations at high baryon density.

Proposals to resolve magnetic instability in gapless superconductors are discussed.

Abstract

We briefly review an effective theory of QCD at high baryon density, describing the relevant modes near the Fermi surface. The high density effective theory has properties of reparametrization invariance and gauge invariance, maintained in a subtle way. It also has a positive measure, allowing lattice simulations at high baryon density. We then apply it to gapless superconductors and discuss recent proposals to resolve the magnetic instability of gapless superconductivity.