Scaling behavior at the N-t=6 chiral phase transition for 2-flavor lattice- art. no. 034508

We have simulated lattice QCD with 2 flavors of massless staggered quarks. An irrelevant chiral 4-fermion interaction was added to the standard quark action to allow us to simulate at zero quark mass. Thermodynamics was studi ed on lattices of temporal extent 6. Clear evidence for a second order chir al transition was observed and the critical exponents beta (mag), delta, nu and gamma (mag) were measured. These exponents do not agree with those exp ected by standard universality arguments. They are, however, consistent wit h tricritical behavior. The pi and sigma screening masses were measured and show clear evidence for chiral symmetry restoration at this transition.