Light quarks in the instanton vacuum at finite baryon density - art. no. 016004

We consider the finite density, zero-temperature behavior of quark matter i n the instanton picture. Since the instanton-induced interactions are attra ctive in both (q) over bar q and qq channels, a competition ensues between phases of matter with condensation in either or both. It results in chiral symmetry restoration due to the onset of diquark condensation, a "color sup erconductor," at finite density. Also possible is a state with both manners of condensation: however, such a phase is at best metastable for any chemi cal potential. The properties of quark matter in each phase are discussed, with emphasis on the microscopic effects of the effective mass and supercon ducting energy gap. [S0556-2821(99)05711-2].