Low‐energy states in ¹¹N and two‐proton emission of ¹²O

We have investigated the low‐energy states of ¹¹N by the elastic scattering method in inverse kinematics using a ¹⁰C beam and a (CD₂)_n target. Recoil protons were detected at 16 laboratory angles θ_lab = 4.6° – 18.9° in a ΔE − E detector system. Using the R‐matrix method to analyse the ¹⁰C + p elastic cross sections, we found ¹¹N to be unbound with respect to proton emission by 1.54±0.02 MeV with a decay width of 0.83±0.03. These results are used to calculate the two‐proton decay width of the ¹²O ground state.