α decay of nuclei in extreme cases

We investigate the recently discovered α decays of heavy and superheavy nuclei with A=160-294 by the cluster model of α decay. This covers the short-lifetime α decays of the nuclei near the proton-drip line, the decays of superheavy elements with Z=106-118, and the long-lifetime decay of the naturally occurring nuclide 180W [Danevich et al., Phys. Rev. C 67, 014310 (2003)]. It is found that the cluster model can well reproduce the new data of half-lives of these nuclei. For superheavy nuclei the cluster model, without introducing any additional adjustments, can reasonably reproduce the half-lives of many nuclei although substantial deviations between experimental half-lives and theoretical ones exist in a few cases in which there may be large errors in the experimental data for a single event. Some new α emitters in naturally occurring nuclides are predicted. Experiments to search the α radioactivity of 176,178Hf and of 149Sm are strongly recommended