Effective lagrangians for QCD at high density

TL;DR

This paper develops effective lagrangians to describe low-energy phenomena in high-density QCD phases, deriving parameters through weak coupling calculations and analyzing phonon behavior in the LOFF phase.

Contribution

It introduces effective lagrangians for CFL and LOFF phases, with a novel derivation of parameters using dimensional reduction and explores phonon properties in the LOFF phase.

Findings

Derived expressions for lagrangian parameters via weak coupling calculations

Identified anisotropic phonon dispersion in the LOFF phase

Provided a framework for low-energy QCD at high density

Abstract

We describe low energy physics in the CFL and LOFF phases by means of effective lagrangians. In the CFL case we present also how to derive expressions for the parameters appearing in the lagrangian via weak coupling calculations taking advantage of the dimensional reduction of fermion physics around the Fermi surface. The Goldstone boson of the LOFF phase turns out to be a phonon satisfying an anisotropic dispersion relation.