Investigating the \(^{13}\)N(\(\alpha , p\))\(^{16}\)O reaction rates via the \(^{19}\)F(p, t)\(^{17}\)F reaction

Abstract

Recent sensitivity studies have shown that nucleosynthesis in Core-collapse supernovae (CCSNe) is significantly influenced by the \(^{13}\)N(\(\alpha , p\))\(^{16}\)O reaction rate. However, the reaction rate at stellar temperatures (up to 4 GK) remains poorly constrained, primarily due to the limited knowledge of the decay properties of relevant \(^{17}\)F resonances above the \(\alpha \) threshold at 5.819 MeV. To improve these constraints, we performed the \(^{19}\)F(\(p, t)^{17}\)F transfer reaction experiment aimed at refining the \(^{13}\)N(\(\alpha , p\))\(^{16}\)O rate. The experiment was performed at the tandem accelerator facility of the Japan Atomic Energy Agency using 30.5-MeV proton beams incident on CaF\(_2\) targets backed with gold. Recoiling tritons from the \(^{19}\)F(\(p, t)^{17}\)F reaction were detected with segmented silicon detector arrays. The triton energy spectra revealed several low-lying \(^{17}\)F states, and angular distributions were analyzed using finite-range Distorted Wave Born Approximation (DWBA) calculations with multiple optical-model parameter sets. Proton and \(\alpha \) decay channels associated with specific \(^{17}\)F resonances were clearly identified, which will allow us to determine the branching ratios. The optimized optical potentials and measured decay yields will provide direct experimental constraints on the \(\alpha \)- and proton-partial widths (\(\Gamma _\alpha \), \(\Gamma _p\)) of \(^{17}\)F levels in the Gamow window (\(E_x\) = 6–9.5 MeV). The resulting resonance parameters will enable a more reliable determination of the \(^{13}\)N(\(\alpha , p\))\(^{16}\)O reaction rate, thereby reducing its current uncertainty in CCSNe nucleosynthesis models.