A NEW SOURCE OF SINGLE PHOTONS FROM Z0 DECAY

A new signal for supersymmetry in Z0 decay is a single photon with large p(T) plus nothing else, arising from the decay mode Z0 --> G-approximately-G-approximately-gamma, where G-approximately is a superlight gravitino. This decay mode is present in a non-minimal supergravity theory with a superlight gravitino, and is not present in the standard model or the usual minimal supergravity theory. For gravitino masses less than 10(-13) GeV, this signal is observable with a million Z0,s for a large region of the supersymmetry parameter space.