Patterns of symmetry breaking in QCD at high baryon density

We study the structure of QCD at very large baryon density for an arbitrary number of flavors N-f. We provide evidence that for any number of flavors larger than N-f = 2 chiral symmetry remains broken at asymptotically large chemical potential. For N-c = N-f = 3, chiral symmetry breaking follows the standard pattern SU(3)(L) x SU(3)(R) --> SU(3), but for N-f > 3 unusual patterns emerge. We study the case N-f = 3 in more detail and calculate the magnitude of the chiral order parameters (<(psi)over bar>psi) and ((<(psi)over bar>psi)(2)) in perturbative QCD. We show that, asymptotically, (<(psi)over bar>psi)(1/3) is much smaller than ((<(psi)over bar>psi)(2))(1/6). The result can be understood in terms of an approximate discrete symmetry. (C) 2000 Elsevier Science B.V. All rights reserved.