Matrix elements relevant for Delta I=1/2 rule and epsilon-prime from   Lattice QCD with staggered fermions
  We perform a study of matrix elements relevant for the Delta I=1/2 rule and the direct CP-violation parameter epsilon-prime from first principles by computer simulation in Lattice QCD. We use staggered (Kogut-Susskind) fermions, and employ the chiral perturbation theory method for studying K to 2 Pi decays. Having obtained a reasonable statistical accuracy, we observe an enhancement of the Delta I=1/2 amplitude, consistent with experiment within our large systematic errors. Finite volume and quenching effects have been studied and were found small compared to noise. The estimates of epsilon-prime are hindered by large uncertainties associated with operator matching. In this paper we explain the simulation method, present the results and address the systematic uncertainties. 
D. Pekurovsky, G. Kilcup (Ohio State University)