Hadron properties in lattice QCD with dynamical fermions

Incorporating dynamical Kogut-Susskind fermions into a Monte Carlo simulation of QCD, we have analyzed the masses of low-lying hadrons, chiral-symmetry breaking, and the interquark potential. We used a 24×${12}^3$ lattice for two couplings $g$, where $\beta =\frac{6}{g^2}=5.20\mathrm{} \mathrm{and} 5.35$. The quark masses were $ma=0.075, 0.050, \mathrm{and} 0.025$ ($a$ being the lattice spacing). We find that the pattern of hadron masses of the $\pi$, $\rho$, and $N$ is qualitatively as seen experimentally. The pion mass squared is proportional to the quark mass and thus behaves as expected from chiral symmetry. Values for the quark condensate extrapolated to $ma=0\mathrm{}$, the renormalization-group-invariant quark mass, and the pion decay constant are in reasonable agreement with values derived from experiment or from current algebra. If we fix the lattice spacing from the $\rho$ mass, we see evidence for the screening effect of light-quark-antiquark pairs in the potential between two massive quarks. At $\beta =5.20\mathrm{}$ and $ma=0.050\mathrm{}$ we find good agreement between the results from our pseudofermion method and those from a hybrid simulation.