Discovery of a new broad resonance in $^{19}$Ne: Implications for the destruction of the cosmic $\gamma$-ray emitter $^{18}$F

Six proton-emitting states in 19Ne were studied through the inelastic scattering reaction H(19Ne; p)19Ne*(p)18F. Their energies and widths were derived from the protons detected at zero degree, while proton-proton angular correlations between the detector at zero degree and a segmented annular detector were used to determine their spin value. Besides the known states, a new broad J = 1/2 resonance has been evidenced at Ex ≈ 7.9 MeV, ≈ 1:45 MeV above the proton emission threshold. By introducing this resonance, the 18F(p; alpha)15O destruction rate in novae is significantly enhanced. This reduces the chance to observe the cosmic gamma-ray emission of 18F from novae in space telescopes.