$^{19}$F$(p,\gamma)$$^{20}$Ne reaction rate and the puzzling calcium abundance in metal poor stars

TL;DR

This study uses the Gamow shell model to theoretically analyze the $^{19}$F$(p, ightarrow)$$^{20}$Ne reaction rate, supporting recent experimental findings and suggesting a possible explanation for calcium abundance in early stars.

Contribution

The paper introduces a GSM-CC theoretical approach to accurately predict the $^{19}$F$(p, ightarrow)$$^{20}$Ne reaction rate, aligning with recent experimental data and implications for stellar nucleosynthesis.

Findings

GSM-CC predicts reaction rates close to JUNA measurements at 0.1 GK.

The reaction may dominate over competing processes, influencing calcium production.

Supports the hypothesis of fluorine breakout contributing to early calcium in stars.

Abstract

The $^{19}$F$(p,\gamma)$$^{20}$Ne reaction is the only process to break out of the CNO cycle at temperature below 0.1 GK and may serve as the origin of calcium in first generation of stars after the Big Bang. In the recent measurement, the Jinping Underground Nuclear Experiment (JUNA) obtained the rate of $^{19}$F$(p,\gamma)$$^{20}$Ne reaction, significantly larger than the previously recommended values. In this work, we perform the theoretical studies of the $^{19}$F$(p,\gamma)$$^{20}$Ne reaction using the Gamow shell model in the coupled-channel representation (GSM-CC). At temperature around 0.1 GK, the predicted rate by GSM-CC is close to the rate found by JUNA. Thus, based on GSM-CC, the break-out reaction $^{19}$F$(p,\gamma)$$^{20}$Ne from the CNO-cycle might win over its competing reaction $^{19}$F$(p,\alpha)$$^{16}$O, and produce enough calcium in the metal poor stars.