More on the QCD phase diagram at finite temperatures

In order to broaden the existing knowledge about the phase diagram of QCD, we use a Langevin algorithm to study finite-temperature QCD on an $8^3$×4 lattice with variable flavor number, quark mass, and gauge coupling. We concentrate on the search for first-order transitions for small flavor number and light-quark masses. We find general agreement with the predictions of effective models of the finite-temperature deconfinement and chiral-symmetry-restoration phase-transition mechanisms. In particular, we find that the deconfinement transition extends to lower quark masses as $n_f$, the number of quark flavors, decreases. Nonperturbative fermionic effects are found to be significant for very light quarks even for $n_f$=0.1. .AE