The CLEO III upgrade

Abstract The CLEO detector at the Cornell Electron Storage Ring (CESR) is completing a major upgrade that significantly extends its physics reach in the study of heavy quarks and leptons. The major elements of this detector upgrade are the installation of a “fast” ring imaging Cherenkov detector, a new central drift chamber and a new barrel-style silicon strip vertex detector. Trigger and data acquisition systems are also upgraded. We summarize the status of these detector subsystems as well as the parallel CESR upgrade.