TOPOLOGY, FERMIONIC ZERO MODES, AND FLAVOR SINGLET CORRELATORS IN FINITE-TEMPERATURE QCD - ART. NO. 054504

We compute the screening correlators in the sigma and eta' flavor sing let channels in finite temperature QCD with 2 light quark flavors. Tog ether with the correlators in the <(pi)over right arrow> and <(delta)o ver right arrow> channels, these are used to discuss several issues re lated to symmetry restoration and the nature of the QCD phase transiti on. Our calculations span a range of temperature extending from approx imately 125 MeV to 170 MeV and are carried out in the context of a sta ggered fermion formulation on a 16(3) x 8 lattice. In addition to the computation at a fixed quark mass (am(q) = 0.00625), we discuss the is sue of the chiral limit. After careful consideration of the zero-mode shift lattice artifact, we present rather strong (topological) argumen ts in favor of the non-restoration of U-A(1) at T-c. [S0556-2821(98)03 517-6]