Study of the unbound nucleus ${}_{}{}^{11}{}_{}{}^{}\mathrm{N}$ by elastic resonance scattering

Resonances in the unbound nucleus ${}_{}{}^{11}{}_{}{}^{}\mathrm{N}$ have been studied, using the resonance scattering reaction ${}_{}{}^{10}{}_{}{}^{}\mathrm{C}$+$p$. The data give evidence for three states above the ${}_{}{}^{10}{}_{}{}^{}\mathrm{C}$+$p$ threshold with energies 1.30, 2.04, and 3.72 MeV. These states can be interpreted, in a potential-model analysis, as the ground state and the first two excited states with spin-parity $\frac{1}{2^{+}}$, $\frac{1}{2^{-}}$, and $\frac{5}{2^{+}}$ arising from the shell-model orbitals $1s_{\frac{1}{2}}$, $0p_{\frac{1}{2}}$, and $0d_{\frac{5}{2}}$. A narrow state superposed on a broad structure found at higher energy could be interpreted as the mirror state of the $\frac{3}{2^{-}}$ in ${}_{}{}^{11}{}_{}{}^{}\mathrm{Be}$ shifted down in energy. This shift would suggest a large radius of the potential.