Structure of Fe 70: Single-particle and collective degrees of freedom

Excited states in the neutron-rich Fe-70 nucleus were populated in a one-proton removal reaction from Co-71 projectiles at 87 MeV/nucleon. A new transition was observed with the gamma-ray tracking array GRETINA and shown to feed the previously assigned 4(1)(+) state. In comparison to reaction theory calculations with shell-model spectroscopic factors, it is argued that the new gamma ray possibly originates from the 6(1)(+) state. It is further shown that the Doppler-reconstructed gamma-ray spectra are sensitive to the very different lifetimes of the 2(+) and 4(+) states, enabling their approximate measurement. The emerging structure of Fe-70 is discussed in comparison to LNPS-new large-scale shell-model calculations.