This award will provide continued support for research at the University of Cincinnati. The primary emphasis is the development and fabrication of equipment for a particle detector, SLD, being built at the Stanford Linear Accelerator Center (SLAC). Data analysis will continue on two other experiments, E135 of the Stanford Linear Accelerator Center and E691 of Fermilab. The group consists of four faculty members, one research associate and two students. Research and development will continue on a system for identifying particles (Cerenkov Ring Imaging Device). Part of this system will be built at Cincinnati to be installed in the SLD in about three years. The SLD is expected to be one of the premier detectors for studying the neutral particle which mediates the weak interaction, the Zo. These studies are expected to contribute to our understanding of the forces of nature, in particular the relationship between the weak and electromagnetic force and elucidate some of the fundamental questions confronting us in elementary particle physics.