Proton decay of states in11N

The proton-unbound nucleus ${}^{11}\mathrm{N}$ has been studied via kinematic reconstruction of the emitted proton in coincidence with the residual ${}^{10}\mathrm{C}$ daughter nucleus. Resonances in ${}^{11}\mathrm{N}$ were populated by using a 40 MeV/nucleon radioactive beam of ${}^{12}\mathrm{N}$ to induce the reaction ${}^9{\mathrm{B}\mathrm{e}(}^{12}{\mathrm{N},}^{11}\mathrm{N}),$ followed by the proton decay of ${}^{11}\mathrm{N}.$ The decay energy spectrum was constructed from the energies and separation angle of the ${}^{10}\mathrm{C}$ and the proton. In addition to protons from the known ${1/2}^{-}$ state, at 2.24 MeV above the proton decay threshold, another peak is seen near 1.45 MeV. This peak could potentially be due to the predicted ${1/2}^{+}$ ground state and/or due to the decay of the ${3/2}^{-}$ state to the first excited state of ${}^{10}\mathrm{C}$