Thermodynamics of lattice QCD with massless quarks and chiral 4-fermion interactions

Nf = 2 lattice QCD with massless quarks and a weak 4-fermion interaction appears to have the expected second order transition, at least for Nt ≥ 6. More work is needed to clarify the Nt = 4 case. With more statistics the Nt = 6 simulations should produce an accurate determination of the critical exponent βm. Moving to finite mass at β = βc should allow an accurate determination of σ. Hadronic screening masses need further analysis. Other order parameters remain to be analyzed. Unfortunately, there is no obvious way to include 4-fermion interactions with full SU(2) x SU(2) chiral flavor symmetry