Quark Condensation, Induced Symmetry Breaking and Color Superconductivity at High Density

Abstract

The phase structure of hadronic matter at high density relevant to the physics of compact stars and relativistic heavy-ion collisions is studied in a low-energy effective quark theory. The relevant phases that figure are (1) chiral condensation, (2) diquark color condensation (color superconductivity) and (3) induced Lorentz-symmetry breaking (ISB). For reasonable strengths for four-Fermi interactions implied by one-gluon exchange quark interactions as well as instanton-mediated interactions, we find that the ISB phase sets in at a moderate density while the quark condensate vanishes, followed by color superconductivity associated with scalar diquark condensation appearing only at an asymptotic density. Lack of confinement in the model makes the result of this analysis only qualitative but the hierarchy of the transitions we find seems to be quite robust.