Color Superconductivity and Signs of its Formation

Abstract

We study finite density QCD in an approximation in which the interaction between quarks is modelled on that induced by instantons. We sketch the mechanism by which chiral symmetry restoration at finite density occurs in this model. At all densities high enough that the chirally symmetric phase fills space, we find that color symmetry is broken by the formation of a $< qq >$ condensate of quark Cooper pairs. The formation of this color superconductor condensate lowers the energy of the system most if the up and down quark chemical potentials are equal. This suggests that the formation of such a condensate in a heavy ion collision may be accompanied by radiation of negative pions, and its decay may yield more protons than were present in the incident nuclei.