Revised Reaction Rate for the Astrophysical Reaction 18O(p, α)15N via a Global R-matrix Analysis

The O-18(p, alpha)N-15 reaction is of particular importance for influencing the abundances of key isotopes such as F-19, O-18, and N-15. Peculiar abundances for these nuclei are observed from spectra or meteorite grains originating in asymptotic giant branch stars. The O-18(p, alpha)N-15 could provide a way to explain the discrepancy between the observations and model predictions. A comprehensive R-matrix analysis has been performed for the O-18(p, alpha)N-15 reaction by including additional constraints from other reaction channels; in particular, the N-15+alpha scattering data were involved in the analysis for the first time. All available data were compiled and used in the R-matrix analysis. The fitted resonance parameters are compared with previous works. A revised determination of reaction rate has been extracted, relying on the present fitting parameters. The uncertainties on the corresponding reaction rates were then obtained by a Monte Carlo analysis.