Anomalous chiral symmetry breaking above the QCD phase transition

We study the anomalous breaking of U-A(1) symmetry just above the QCD phase transition for zero and two flavors of quarks, using a staggered fermion, lattice discretization. The properties of the QCD phase transition are expe cted to depend on the degree of U-A(1) symmetry breaking in the transition region. For the physical case of two flavors, we carry out extensive simula tions on a 16(3) x 4 lattice, measuring a difference in susceptibilities wh ich is sensitive to U-A(1) symmetry and which avoids many of the staggered fermion discretization difficulties. The results suggest that anomalous eff ects are at or below the 15% level.