Z = 110–111 elements and the stability of heavy and superheavy elements

The recent discovery of isotopes with Z = 110–111 is consistent with (1) a monopole-monopole interaction that does not appear explicitly in Nilsson-Strutinsky mass systematics, and (2) a competition between SU(2) and SU(3) dynamical symmetries that has been predicted for this region. Our calculations suggest that these new isotopes are near spherical, and may represent a true island of superheavy nuclei, but shifted downward in neutron number by these new physical effects.