Asymptotic Deconfinement in High-Density QCD

We discuss QCD with two light flavors at large baryon chemical potential μ. Color superconductivity leads to partial breaking of the color SU(3) group. We show that the infrared physics is governed by the gluodynamics of the remaining SU(2) group with an exponentially soft confinement scale Λ_QCD^′∼Δexp[-aμ/(gΔ)], where Δ≪μ is the superconducting gap, g is the strong coupling, and a = 2√2π/11. We estimate that, at moderate baryon densities, Λ_QCD^′ is O(10 MeV) or smaller. The confinement radius increases exponentially with density, leading to “asymptotic deconfinement.” The velocity of the SU(2) gluons is small due to the large dielectric constant of the medium.