Dynamical lattice QCD thermodynamics and the U(1)_A symmetry with domain wall fermions

Abstract

Results from numerical simulations of full, two flavor QCD thermodynamics at N_t=4 with domain wall fermions are presented. For the first time a numerical simulation of the full QCD phase transition displays a low temperature phase with spontaneous chiral symmetry breaking but intact flavor symmetry and a high temperature phase with the full $SU(2) \times SU(2)$ chiral flavor symmetry. It is found that close to the transition in the high temperature phase the U(1)_A axial symmetry is broken only by a small amount. This result is of particular interest because of the connection between U(1)_A symmetry breaking and the expected order of the transition.