SEARCH FOR HEAVY STABLE PARTICLES

A search is made for cosmic ray produced heavy stable particles of unit positive charge in terrestrial water. By electrolysis of 6000 litres of heavy water, small samples are produced with a heavy isotope enrichment factor 3 · 1011 relative to natural water. Comparison of enriched and unenriched samples in a sensitive mass spectrometer showed no evidence for new particles in the mass range 6 to 350 proton masses, giving upper concentration limits in natural water between 2 · 10-22 and 10-21 over most of the mass range. An experiment to improve this limit by a factor of 106 is in progress. © 1979.