We search for physics beyond the standard model using events with a photon, two or more hadronic jets, and an apparent imbalance in transverse energy, in $p\bar{p}$ collisions at the Fermilab Tevatron at $\sqrt{s}=1.8$ TeV. Such events are predicted for production of supersymmetric particles. No excess is observed beyond expected background. For the parameter space of the minimal supersymmetric standard model with branching fraction $B(\tilde��^0_2 \to ��\tilde��^0_1) = 1$ and $m_{\tilde��^0_2}-m_{\tilde��^0_1}>20$ GeV, we obtain a 95% confidence level lower limit of 310 GeV for the masses of squarks and gluinos, where their masses are assumed equal.

6 pages, 3 figures, submitted to Phys. Rev. Letters, fixed one reference