A QUARK-ANTIQUARK CONDENSATE IN 3-DIMENSIONAL QCD

Three-dimensional lattice QCD is studied by Monte Carlo simulations wi thin the quenched approximation. At zero temperature a quark-antiquark condensate is observed in the limit of vanishing quark masses. The co ndensate vanishes continuously at the finite-temperature deconfinement phase transition of the theory. A. natural interpretation of this phe nomenon in the full theory with dynamical quarks is in terms of the sp ontaneous flavor symmetry breaking U(N-f) --> U(N-f/2) x U(N-f/2). In addition, the spectrum of low-lying Dirac operator eigenvalues is comp uted and found to be consistent with a flat distribution at zero tempe rature, in agreement with analytical predictions. (C) 1998 Elsevier Sc ience B.V. All rights reserved.