Supersymmetric (SUSY) standard models in which the lightest SUSY particle (LSP) is an ultralight gravitino (m_{ 3/2}=O(1) eV) are very attractive, since they are free from the cosmological gravitino problems. If the neutralino is the next lightest SUSY particle (NLSP), it decays into a photon and the gravitino in collider experiments. We propose a simple test for the lightness of gravitino at the LHC.
Categories: hep-ph