Search for Superheavy Elements in the Bombardment of 248Cm with 48Ca

We have searched for superheavy elements 110 to 116 with half-lives between 10⁴ and 10⁸ s in fractions chemically separated after each of a series of bombardments of ²⁴⁸Cm made with 267-MeV ⁴⁸Ca ions. After 6 months of α and spontaneous-fission counting, our results provide no persuasive evidence for the presence for the presence of superheavy elements. The most plausible explanation for not finding the superheavy elements is that they have either short half-lives or very small formation cross sections.