Fission Time Measurements: A New Probe into Superheavy Element Stability

Reaction mechanism analyses performed with a 4{pi} detector for the systems {sup 208}Pb+Ge, {sup 238}U+Ni and {sup 238}U+Ge, combined with analyses of the associated reaction time distributions, provide us with evidence for nuclei with Z=120 and 124 living longer than 10{sup -18} s and arising from highly excited compound nuclei. By contrast, the neutron deficient nuclei with Z=114 possibly formed in {sup 208}Pb+Ge reactions have shorter lifetimes, close to or below the sensitivity limit of the experiment.