Spectroscopy of Element 115 Decay Chains

A high-resolution alpha, x-ray, and gamma-ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fur Schwerionenforschung. Thirty correlated alpha-decay chains were detected following the fusion-evaporation reaction Ca-48(+) Am-243. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.