DECAY PROPERTIES AND STABILITY OF HEAVIEST ELEMENTS

Deca properties and stability of heaviest nuclei with Z <= 132 are studied within the macro-microscopical approach for nuclear ground state masses and phenomenological relations for the half-lives with respect to alpha-decay, beta-decay and spontaneous fission. We found that at existing experimental facilities the synthesis and detection of nuclei with Z > 120 produced in fusion reactions may be difficult due to their short half-lives (shorter than 1 mu s). The nearest (more neutron-rich) isotopes of superheavy elements with 111 <= Z <= 115 to those synthesized recently in Dubna in Ca-48-induced fusion reactions are found to be beta(+)-decaying. This fact may significantly complicate their experimental identification. However it gives a chance to synthesize in fusion reactions the most stable superheavy nuclei located at the center of the island of stability. Our calculations yield that the beta-stable isotopes (291)Cn and (293)Cn with a half-life of about 100 years are the longest-living superheavy nuclei located at the island of stability.