Searches for prompt light gravitino signatures in e+e- Collisions at   sqrt{s}=189GeV
  Searches for final states expected in models with light gravitinos have been performed, including experimental topologies with multi-leptons with missing energy, leptons and photons with missing energy, and jets and photons with missing energy. No excess over the expectations from the Standard Model has been observed. Limits are placed on production cross-sections in the different experimental topologies. Additionally, combining with searches for the anomalous production of lepton and photon pairs with missing energy, results are interpreted in the context of minimal models of gauge mediated SUSY breaking. Exclusion limits are established at the 95% confidence level on the supersymmetric particle masses; m-slepton > 83 GeV and m-neutralino > 85 GeV for tan(beta)=2, m-stau > 69 GeV, m-selectron,-smu > 88 GeV and m-neutralino > 76 GeV for tan(beta)=20. 
The OPAL collaboration, G.Abbiendi, et al