The structure of 70Fe: Single-particle and collective degrees of freedom

Abstract

Excited states in the neutron-rich \nuc{70}{Fe} nucleus were populated in a one-proton removal reaction from \nuc{71}{Co} 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 \nuc{70}{Fe} is discussed in comparison to LNPS-new large-scale shell-model calculations.

arXiv commentaccepted for publication as PRC rapid communication

References in corpus (6)

• Systematics of intermediate-energy single-nucleon removal cross sections
• Shape Coexistence in 78 Ni and the new Island of Inversion
• Observation of isotonic symmetry for enhanced quadrupole collectivity in neutron-rich 62,64,66Fe isotopes at N=40
• Sensitivity of the r-process to nuclear masses
• Nuclear Structure Towards N=40 60Ca: In-beam gamma-ray Spectroscopy of 58,60Ti
• Beta decay of 71,73Co; probing single particle states approaching doubly magic 78Ni

Cited by in corpus (7)

• Quenching of single-particle strength from direct reactions with stable and rare-isotope beams
• The Neutron-Rich Edge of the Nuclear Landscape. Experiment and Theory
• Updated systematics of intermediate-energy single-nucleon removal cross sections
• UCGretina GEANT4 Simulation of the GRETINA Gamma-Ray Energy Tracking Array
• Exploiting dissipative reactions to perform in-beam $\gamma$-ray spectroscopy of the neutron-deficient isotopes \nuc{38,39}{Ca}
• Probing the role of proton cross-shell excitations in 70Ni using nucleon knockout reactions
• Persistence of the $Z=28$ shell gap in $A=75$ isobars: Identification of a possible $(1/2^{-})$ $\mu$s isomer in ${}^{75}$Co and $\beta$ decay to ${}^{75}$Ni