Tau physics

At present, CLEO II is providing competitive information on almost every aspect of physics including decays, lifetime, and mass. With the improved CESR luminosity, CLEO will continue to have the largest sample in the world. The addition of particle identification will increase the number of modes that will be measured well. One measurement which should continue to improve is the limit on the mass. In particular, the mode will provide a good limit because of the large hadronic mass and the reasonable rate; the mode is another good possibility. Each utilizes different aspects of the detector performance.

Much of the advantage that CLEO has in measuring or branching ratios is its good efficiency and resolution for events with one or more neutrals. We have ensured that in optimizing other, newer aspects of the detector, we lose no performance in this area. A good test of this is the decay mode , which requires a final state with four photons. In all cases the CLEO III detector meets or exceeds the performance of CLEO II.