I have estimated the energies of several unbound states of ${}^{12}\mathrm{Be}$ and their spectroscopic factors for decay to the $1/2^{+}$ ground state and $1/2^{-}$ first-excited state of ${}^{11}\mathrm{Be}$. These are then used to estimate the expected widths for such decays. Results for likely $3^{-}$ and $4^{+}$ states are good. I find that only $0^{+}$ and/or $2^{+}$ states can account for the width recently observed for a state decaying with a centroid neutron energy of 1.24 MeV.

• Received 16 January 2016

DOI:https://doi.org/10.1103/PhysRevC.93.034325