SUPERSYMMETRIC SIGNALS IN GAMMA-GAMMA COLLISIONS

We study the occurrence of final states with only an electron-positron pair and missing transverse momentum as a signal of supersymmetry in photon-photon collisions. Suitable high-energy photon beams may be provided at linear colliders by back-scattering laser beams on electron beams. The final states considered represent a typical signature for the production and decay of selectron and chargino pairs within the minimal supersymmetric standard model. We show that, away from the kinematical threshold, selectrons produce this signal far more abundantly than charginos. The standard model background is dominated by W-pair production. We propose a series of kinematical cuts which reduce this background to an acceptable level. With a 1 TeV collider operated in the gammagamma mode, we find that interesting and complementary tests of supersymmetric models can be performed for selectron masses up to 350 GeV.