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

Abstract

The ^18 O( p , α ) ^15 N reaction is of particular importance for influencing the abundances of key isotopes such as ^19 F, ^18 O, and ^15 N. Peculiar abundances for these nuclei are observed from spectra or meteorite grains originating in asymptotic giant branch stars. The ^18 O( p , α ) ^15 N could provide a way to explain the discrepancy between the observations and model predictions. A comprehensive R -matrix analysis has been performed for the ^18 O( p , α ) ^15 N reaction by including additional constraints from other reaction channels; in particular, the ^15 N+ α 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.

Keywords

• Nuclear reaction cross sections
• Reaction rates
• Stellar nucleosynthesis