Nature of the finite temperature transition in QCD with strange quark

Abstract

The finite temperature transition in QCD is studied using Wilson quarks for the cases of $N_F=2$, 3 and 2+1. For $N_F=2$ the transition is smooth in the chiral limit on both $\text{nt}=4$ and 6 lattices. For $N_F=3$, clear two state signals are observed for $\beta \le 4.7$ on $8^2\times 10\times 4$ and $12^3\times 4$ lattices, which implies the transition is first order for $m_q\text{simm}<140$ MeV. For $N_F=2+1$ we study two cases of $m_s\simeq 150$ and 400 MeV with $m_u=m_d\simeq 0$. In contrast to a previous result with staggered quarks, two state signals are clearly observed for both cases, suggesting a first order QCD phase transition in the real world.

Comments: ps file, 3 pages with 4 figures