Evidence for superheavies in mica looks weaker

Last June when evidence for the presence in several mica samples of element 126 and possibly numbers 116, 124 and 127 was reported, great excitement was generated (PHYSICS TODAY, August 1976, page 17). The experiment, by a collaboration from Oak Ridge, University of California at Davis and Florida State University, had been done by bombarding the sample with protons and looking for characteristic x rays from elements between Z = 105 and Z = 134. Now a variety of follow-up experiments have been done by members of the original team and by other groups, all of which suggest that the evidence for superheavies is weaker than before.