Searching for supermassive Cahn-Glashow particles

A radiochemical technique, based on the ¹⁴N(n,p)¹⁴C reaction, has failed to detect the presence of supermassive negatively charged particles (X^-) in terrestrial carbon. The limits of X^- per nucleon of {~}2 ×{} 10^-15 are applicable to masses less than {~}10⁵ amu. These limits are orders of magnitude lower than previously reported for X^- particles of this mass range bound to light nuclei in terrestrial samples. Examination of the geochemical and nucleosynthetic history of such particles suggests that, if present, they should be depleted in light elements and concentrated in elements of the iron region, possibly in meteorites.