Lattice Field Theory and Hadronic Physics

Florida International University, Miami FL

Investigators

Abstract

Considerable theoretical progress combined with enormous advances in computer technology has made lattice .eld theory a powerful tool in the study of nuclear and sub-nuclear structure. The proposed activity has the following intellectual merits: i) proposal of new ideas and exploration of new theoretical approaches to compute interesting novel physical quantities; ii) use of existing techniques along with state-of-the-art computers to obtain results of experimental interest. Calculations in lattice QCD are often performed in the quenched approximation. Quenching e.ects will be studied in detail using lattice fermions that have exact chiral symmetry. Calculations beyond the quenched approximation are computationally intensive and planar QCD will be studied to see if it is a physically viable alternative. Exotic hybrid mesons contain valence gluons and can only be studied properly in the framework of QCD. Experiments scheduled in Hall D at JLab plan to look for such exotic hybrid mesons. Computations of their decay widths will be performed to provide some guidance for the experimental searches of these exotic hybrids. Lattice QCD will be used to study nuclear forces present in a two hadron system. It will also be used to study the electric and magnetic polarizabilities of hadrons. These computations are technically involved and results would considerably increase our understanding of nuclear interactions from .rst principles. Chiral symmetry in QCD is spontaneously broken at low temperatures but it is expected to get restored at high temperatures. QCD at high temperatures is described by a quark-gluon plasma. The physics around the chiral phase transition will be investigated using lattice QCD with chiral fermions. The role of instantons at .nite temperature will be carefully studied. The proposed research will greatly bene.t from the participation of a fulltime postdoctoral fellow and a graduate student. The graduate student working in close association with the PIs and the postdoctoral fellow will become familiar with the research done at the forefront of nuclear theory and also get a good training in the use of state-of-the-art parallel computing resources. As part of the outreach program, a senior physics student will be employed to set up a website describing the projects at a level that is accessible to high school students, teachers and the local community at large. By focusing on high pro.le topics currently of great interest at national laboratories, the proposal hopes to assist in the e.orts of the local university to attract new students from underrepresented groups.