Search for New Particles at the Alternating-Gradient-Synchrotron Beam Dump

This paper presents results of a beam-dump experiment performed at the Brookhaven alternating-gradient synchrotron to search for prompt sources of neutrinos and axionlike particles. We observe no excess of ${\nu }_e$ or ${\overline{\nu }}_{\mu }$ events, and no excess in neutral-current events over that expected from neutrinos from $\pi$ and $K$ decays. We report on limits of prompt particle-production cross sections and lifetimes.