QCD thermodynamics with eight staggered quark flavors on a 16(3) x 6 lattice.

Abstract

The results of our investigations on the finite-temperature phase structure of QCD with eight relatively light dynamical quark flavors on a 16{sup 3}{times}6 lattice are reported. Similar to our previous work on a 16{sup 3}{times}4 lattice, a clear first-order phase transition associated with chiral symmetry is found: by looking at the behavior of the chiral condensate we are able to show the coexistence of two metastable phases at a quark mass {ital m}{sub {ital q}a}=0.05. This suggests that the chiral phase transition grows stronger with an increasing number of quark flavors. On the other hand, we could not find a clear signal for the first-order phase transition with {ital m}{sub {ital q}a}=0.1, suggesting that the transition weakens with an increasing quark mass. These conclusions are also supported by the behavior of the quark and gluon internal energy densities as well as that of the Polyakov line.