Mass and Lifetime Limits on Supersymmetric Particles from a Proton Beam-Dump Experiment

Muonless events from the prompt-neutrino experiment at Fermilab have been analyzed to set limits on the masses and decays of supersymmetric particles by means of three measurements: (1) the $\frac{{\nu }_e}{{\nu }_{\mu }}$ ratio, (2) the rate of events consisting of electromagnetic showers only, and (3) the event rate at large transverse momentum. These limits are based upon the absence of events above our visible energy cutoff of 20 GeV which could be attributed to supersymmetry. Several hypotheses concerning supersymmetric particle decays are considered.