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We have searched for the production and decay of light supersymmetric baryons produced in 800 GeV͞c proton copper interactions in a charged hyperon beam experiment. We observe no evidence for the decays R 1 ͑uudg͒ ! S 0 ͑udsg͒p 1 and X 2 ͑ssdg͒ ! S 0 ͑udsg͒p 2 in the parent mass and lifetime ranges of 1700 2500 MeV͞c 2 and 50 -500 ps. Production upper limits for R 1 at x F 0.47, P t 1.4 GeV͞c 2 and X 2 at x F 0.48, P t 0.65 GeV͞c 2 of less than 10 23 of all charged secondary particles produced are obtained for all but the highest masses and shortest lifetimes predicted. [S0031-9007(97)03037-8] PACS numbers: 13.85.Rm, 14.80.LyRecent theoretical work [1-3] has proposed a supersymmetric model with a light gluino ͓g͔ in the mass range 100 600 MeV͞c 2 . A direct consequence of this model is the prediction of a set of supersymmetric hadrons in the 1000 3000 MeV͞c 2 mass range. We have searched for two weak decay modes between these hadrons in an attempt to either confirm this hypothesis or close the low mass window for supersymmetry.Among the light hadrons predicted [1-3] are the supersymmetric partners of the proton R 1 ͑uudg͒; J 2 , X 2 ͑ssdg͒; as well as the S 0 ͑udsg͒. Characteristically, the predicted mass and lifetime ranges for those states which have weak decays are 1700 2500 MeV͞c 2 and 50-500 ps. The mass splitting predicted [3] between the R 1 and S 0 is DM RS M R 1 2 M S 0 210 6 20 MeV͞c 2 . The S 0 is less massive than the R 1 in this model [3] due to the very strong attraction of the flavor singlet quarks in the S 0 . In this model this state is the lowest mass superbaryon. Only strangeness changing weak decays are allowed between the lowest mass superbaryons, unless the mass splittings are large enough to allow strong decay by kaon emission. If the mass splittings are similar to the hyperon system, as expected for the R 1 -S 0 system, the lifetimes and decay modes of the superbaryons should mimic the hyperons. Limits on the production rate of R 1 and X 2 as a function of mass and lifetime can be set in charged hyperon beam searches. We report such a search. We have not assumed the predicted mass splitting; we perform the search as a function of this parameter. For DM RS less than M p the R 1 decay is forbidden. For M p , DM XS , M K the X 2 is stable against strong decay via kaon emission and weak decay via pion emission is allowed. We assume the dominant decays are R 1 ! S 0 p 1 and X 2 ! S 0 p 2 analogous to the normal hyperon decays S 1 ! np 1 and J 2 ! L 0 p 2 .Fermilab experiment E761 was a high statistics study of hyperon radiative decays. We reconstructed [4] 48 3 10 6 S 1 ! pp 0 and 38 3 10 3 S 1 ! pg decays from data taken in 1990. Unfortunately, this data set cannot be used for an R 1 search, since the trigger required a photon in the final state. In our observation of the J 2 ! S 2 g decay [5] we took negative beam data in a different configuration of the apparatus. This had good acceptance for low momentum charged secondaries but also required a photon trigger. In order to control the photon ...

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