Search for anomalous multiphoton production at 100–300 GeV

We have carried out a search for anomalous multiphoton production in neutron-Ch₂ collisions at Fermilab. Both anomalous γ events as might be produced in the annihilation of a magnetic monopole pair, as well as events with smaller opening angles, such as those observed in cosmic ray emulsions by Schein et al. and others were sought. No evidence for either type of event was found. An upper limit ～2.7 μb is placed on the production cross section for “Schein” events or ～10^?2 that deduced from the cosmic ray data.