Search for H dibaryon by scintillating-fiber track detector

Summary  The H dibaryon search experiment using a scintillating-fiber target was performed at KEK-PS. The preliminary results are reported. No evidence of the H production via C(K−, K+) reaction has been found. The upper limit of the ratio of the H production to the quasi-free process, K−+(p)→K++Ξ− is 0.05–0.6% forM H⩽2200 MeV/c2. For 2200 MeV/c2⩽MH⩽2230 MeV/c2, the upper limit for the production of the H which decays into Σ−+p is 0.6–07%.