Particle Physics and Lattice Gauge Theory

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

Over the last several years the structure of the QCD vacuum over different length scales and the mechanisms of confinement have been the focus of intense activity among workers in lattice gauge theory. Lattice gauge theory provides the only available framework for the quantitative investigation of such entirely nonperturbative phenomena. Research in this project is in the areas of QCD improved actions; confinement and QCD vacuum physics; deconfinement transition dynamics; and the quark-gluon plasma in heavy ion collisions. A goal of the proposed research is to further develop systematic procedures that connect the short distance (perturbative) to the long distance (non-perturbative) confining regime in the QCD vacuum. It thus contributes towards directly extracting confinement from QCD, a long-standing goal of theoretical particle physics. It also leads to the construction of improved actions on coarser lattices for accurate determination of string tensions and other observables with reduced discretization errors and computational effort. The second area of the project is that of deconfinement dynamics and heavy ion collisions. The recent experimental discoveries at the Relativistic Heavy Ion Collider (RHIC) have generated wide interest. In particular, the mechanism responsible for the apparent very rapid thermalization in the resulting strongly-coupled quarkgluon plasma above deconfinement remains an unresolved question and the focus of intense activity. Simulation methods for non-equilibrium field theory must be developed to properly address such questions. In this project such novel methods are to be investigated by detailed lattice studies that are a natural continuation of simulations on deconfinement dynamics under previous NSF support. Broader Impacts of this project are that the proposed research in Lattice Gauge Theory involves state-of-the-art methods in Computational Physics that are of wide applicability in the Natural and Biological Sciences and Engineering. As such it provides excellent training in such techniques to graduate students and postdoctoral fellows. For example, graduate students engaged in previously funded projects by this investigator are currently active in engineering and biological research projects. The project can also serve, as it has in the recent past, as a source for mini projects in computation and statistical physics at the upper division undergraduate level. The interplay between experimental discoveries (RHIC) and theoretical/computational physics present in this project has also provided illustrative material for the principal investigator's outreach activities to high school science teachers and students.