Deconfining Chiral Transition in QCD on the Lattice

Abstract

The deconfining chiral transition in finite-temperature QCD is studied on the lattice using Wilson quarks. After discussing the nature of chiral limit with Wilson quarks, we first study the case of two degenerate quarks NF=2, and find that the transition is smooth in the chiral limit on both Nt=4 and 6 lattices. For NF=3, on the other hand, clear two state signals are observed for mq≲140 MeV on Nt=4 lattices. For a more realistic case of NF=2+1, i.e. two degenerate u and d-quarks and a heavier s-quark, we study the cases ms≃150 and 400 MeV with mu=md≃0: In contrast to a previous result with staggered quarks, clear two state signals are observed for both cases, suggesting a first order QCD phase transition in the real world.