Search for Superheavy Nuclei

We describe the discoveries of new superheavy nuclei (a) with Z=107–112 produced in cold fusion reactions between 208 Pb and 209 Bi and beams of A > 50 and (b) with Z=113–118 in hot fusion reactions between actinide nuclei and 48 Ca. We also discuss the facilities used in these measurements. We compare the behavior of the α-decay energies and half-lives, spontaneous fission half-lives, cross sections, and excitation functions with expectations from theoretical calculations. Finally, we outline future research directions, including studies of the detailed properties of nuclei synthesized at higher yields, searches for new elements with Z=119 and 120, and developments of new facilities.