  We describe how one may employ a very simple event selection, using only the
kinematic variable mT2, to search for new particles at the LHC. The method is
useful when searching for evidence of models (such as R-parity conserving
supersymmetry) which have a Z2 parity and a weakly-interacting lightest
parity-odd particle. We discuss the kinematic properties which make this
variable an excellent discriminant against the great majority of Standard Model
backgrounds. Monte Carlo simulations suggest that this approach could be used
to discover supersymmetry with somewhat smaller integrated luminosities (or
perhaps lower center-of-mass energies) than would be required for other
comparable analyses.
