1999/09/21 by D. Pekurovsky, Dmitry Pekurovsky, Pekurovsky, D.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-lat
paper · pdf · doi:10.48550/arxiv.hep-lat/9909141
106 pages, Ph. D. dissertation
arxiv created 1999/09/21 · openalex publication_date 1999/09/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This thesis presents the setup and results of numerical calculation of hadronic matrix elements of Delta S=1 weak operators, with the aim of studying the Delta I=1/2 rule and direct CP violation. Such study provides a useful comparison of the Standard Model predictions with experiment. We work within the framework of (partially quenched) Lattice QCD with the staggered (Kogut-Susskind) version of fermions. We have achieved a reasonable statistical accuracy in calculating all matrix elements in question. Based on these results, we find that the Delta I=1/2 channel in K to 2 Pi decays is enhanced compared to the Delta I=3/2 channel. This is consistent with experiment, although the exact amount of enhancement is subject to considerable systematic errors. I also discuss the difficulties encountered in attempting to calculate the direct CP violation parameter epsilon-prime and our approximate solution leading to a crude estimate. In a related study we nonperturbatively compute bilinear renormalization factors ZS and ZP, which are needed for our estimate of epsilon-prime and also allow to calculate the light quark masses. For the strange quark mass in NDR MS-bar scheme at 2 GeV in the quenched approximation we find: ms = 102.9 +/- 5.1 MeV.