LATTICE QCD WITH 8 LIGHT-QUARK FLAVORS

QCD with eight flavors is studied on 16(3) x N(t) lattices with N(t) = 4, 6, 8, 16, and 32, a dynamical quark mass ma = 0.015, and lattice coupling beta = 6/g2 between 4.5 and 5.0. For N(t) = 16 and 32, hadron masses and screening lengths are computed for a variety of valence quark masses. The previously observed, strong, first-order transition for N(t) = 4, 6, and 8 is seen, for N(t) = 16, to become a beta-independent, zero-temperature transition characterized by a factor of almost-equal-to 3 change in lattice scale. This strong, first-order transition restores chiral symmetry, at least for N(t) = 4, 6, and 8, producing a chirally symmetric, weak-coupling phase. However, as N(t) increases to 16, the chiral-symmetry properties of the weak-coupling side of the zero-temperature transition are unclear and offer a hint of a normal, finite-temperature, chiral-symmetry-breaking transition in the weak-coupling phase.