H particle searches at Brookhaven

Following the suggestion by R.L. Jaffe twenty years ago, researchers have been trying to establish the existence of a six-quark object, termed the H dibaryon, predicted by the phenomenological quark bag model. This object quickly became the focus of experimental searches at several locations, including the AGS. This search still continues, with perhaps the most active program being carried out at the 2.0 GeV/c beam line at the BNL-AGS. The research was considerably enhanced by the writing of two notable papers at BNL by Aerts and Dover, which gave quantitative predictions for H-production cross sections in two very different reaction mechanisms. One of these, the formation of cascade atomic deuterium to form the H by fusion, had been first suggested by P.D. Barnes. The 2.0 GeV/c line at the AGS was specifically designed to provide an adequate kaon flux for double strangeness and charge exchange reactions. It has been used for two H searches, E813 and E836, as well as for several {Lambda}{Lambda} searches, E885 and E906. These four experiments are setting significant limits on H-production. The results of these experiments are discussed, and descriptions of related H searches at Brookhaven are given