Events with large missing transverse energy at the CERN collider: III. Mass limits on supersymmetric particles

Abstract A sample of events with large missing transverse energy from 715 nb −1 of data from the UA1 experiment at the CERN proton-antiproton collider is used to search for evidence of supersymmetric particle production. Assuming that the photino is the lightest supersymmetric particle and that it is massless, we find a limit on the squark mass of m q >45 GeV /c 2 at 90% CL, independently of the gluino mass. Similarly, we find a limit on the gluino mass of m g >53 GeV /c 2 (at 90% CL) independently of the squark mass, provided that the gluino is not long-lived (i.e. provided that the squark is not too heavy, m q ⪅1 TeV /c 2 ). For equal squark and gluino masses we find a limit m q =m g >75 GeV /c 2 at 90% CL. The effect of a non-zero photino mass on these limits is studied.