Search for New Metastable Particles Produced in Au + Au Collisions at10.8AGeV/c

We have investigated particle production using a zero degree two-segment focusing beam-line spectrometer, examining $2\times {10}^{12}\mathrm{Au}+\mathrm{Au}$ interactions at a beam momentum of $10.8A\mathrm{GeV}/c$. We have measured invariant cross sections for protons, various light nuclei (through $A=6\mathrm{}$), antiprotons, and have set upper limits on the production of heavier nuclei, antideuterons, and strangelets. There is no evidence, within the sensitivity of our measurements, for the formation of new particles having lifetimes $>100\mathrm{ns}$