Lattice QCD with eight Hght-quark flavors

Abstract

QCD with eight flavors is studied on 163×Nt lattices with Nt=4,6, and 8, a dynamical quark mass ma=0.015, and lattice coupling =6g2 between 4.5 and 5.0. For Nt=16, hadron masses and screening lengths are computed for a variety of valence quark masses. The previously observed, strong, first-order transition for Nt=4,6, and 8 is seen, for Nt=16, to become a -independent, zero-temperature transition characterized by a factor of 3 change in lattice scale. This strong, first-order transition restores chiral symmetry, at least for Nt=4,6, and 8, producing a chirally symmetric, weak-coupling phase. However, as Nt 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. © 1992 The American Physical Society.