Structure of Superheavy Nuclei Along Element 115 Decay Chains

A recent high-resolution alpha, X-ray, and gamma-ray coincidence-spectroscopy experiment offered the first glimpse of excitation schemes of isotopes along alpha-decay chains of Z = 115. To understand these observations and to make predictions about shell structure of superheavy nuclei below (288)115, we employ two complementary mean-field models: the self-consistent Skyrme energy density functional approach and the macroscopic-microscopic Nilsson model. We discuss the spectroscopic information carried by the new data. In particular, candidates for the experimentally observed E1 transitions in (276)Mt are proposed. We find that the presence and nature of low-energy E1 transitions in well-deformed nuclei around Z = 110, N = 168 strongly depends on the strength of the spin-orbit coupling; hence, it provides an excellent constraint on theoretical models of superheavy nuclei. To clarify competing theoretical scenarios, an experimental search for E1 transitions in odd-A systems (275,277)Mt, (275)Hs, and (277)Ds is strongly recommended.