Observation of theN11Ground State

The ground state of the proton-rich, unbound nucleus ${}^{11}\mathrm{N}$ was observed, together with six excited states using the multinucleon transfer reaction ${}^{10}\mathrm{B}{(}^{14}\mathrm{N}{,}^{13}\mathrm{B}{)}^{11}\mathrm{N}$ at $30A$ MeV incident energy at Grand Accélérateur National d'Ions Lourds. Levels of ${}^{11}\mathrm{N}$ are observed as well defined resonances in the spectrum of the ${}^{13}\mathrm{B}$ ejectiles. They are localized at 1.63(5), 2.16(5), 3.06(8), 3.61(5), 4.33(5), 5.98(10), and 6.54(10) MeV above the ${}^{10}\mathrm{C}+p$ threshold. The ground-state resonance has a mass excess of 24.618(50) MeV; the experimental width is smaller than theoretical predictions.