Phase structure of QC2D at high temperature and density

TL;DR

This paper investigates the phase diagram of two-color QCD with two flavors, revealing a superfluid phase at intermediate chemical potential and low temperature, a deconfined quark matter phase at higher T and mu, and the persistence of heavy quarkonium states across phases.

Contribution

It provides the first detailed lattice study of the phase structure of QC2D at high temperature and density, including superfluid and deconfined phases, with analysis of quarkonium states.

Findings

Identification of a superfluid phase with BCS condensate

Deconfinement temperature decreases slowly with chemical potential

Heavy quarkonium states persist across phases

Abstract

We study two-color QCD with two flavors of Wilson fermion as a function of quark chemical potential mu and temperature T. We find evidence of a superfluid phase at intermediate mu and low T where the quark number density and diquark condensate are both very well described by a Fermi sphere of nearly-free quarks disrupted by a BCS condensate. This gives way to a region of deconfined quark matter at higher T and mu, with the deconfinement temperature decreasing only very slowly with increasing chemical potential. We find that heavy quarkonium bound states persist in the S-wave channels at all T and mu, with an energy reflecting the phase structure. P-wave states appear not to survive in the quarkyonic region.