A Measurement of Neutralino Mass at the LHC in Light Gravitino Scenarios
  We consider supersymmetric (SUSY) models in which a very light gravitino is the lightest SUSY particle. Assuming that a neutralino is the next-to-lightest SUSY particle, we present a measurement of the neutralino mass at the LHC in two photons + missing energy events, which is based on the MT2 method. It is a direct measurement of the neutralino mass itself, independent of other SUSY particle masses and patterns of cascade decays before the neutralino is produced. 
Koichi Hamaguchi, Eita Nakamura and Satoshi Shirai