Reaction rates for the $^{39}$K(p,$\gamma$)$^{40}$Ca reaction

TL;DR

This paper reevaluates the $^{39}$K(p,$ ext{γ}$)$^{40}$Ca reaction rate, highlighting its larger uncertainty and importance in understanding nucleosynthesis in globular clusters, especially the magnesium-potassium anti-correlation.

Contribution

It provides a new evaluation of the $^{39}$K(p,$ ext{γ}$)$^{40}$Ca reaction rate considering data uncertainties, emphasizing the need for further experimental measurements.

Findings

Uncertainty in the reaction rate is larger than previously thought.

The reaction rate significantly influences nucleosynthesis models.

Future experiments should focus on measuring the $^{39}$K(p,$ ext{γ}$)$^{40}$Ca cross section.

Abstract

The magnesium-potassium anti-correlation observed in globular cluster NGC2419 can be explained by nuclear burning of hydrogen in hot environments. The exact site of this nuclear burning is, as yet, unknown. In order to constrain the sites responsible for this anti-correlation, the nuclear reactions involved must be well understood. The $^{39}$K+p reactions are one such pair of reactions. Here, we report a new evaluation of the $^{39}$K(p,$\gamma$)$^{40}$Ca reaction rate by taking into account ambiguities and measurement uncertainties in the nuclear data. The uncertainty in the $^{39}$K(p,$\gamma$)$^{40}$Ca reaction rate is larger than previously assumed, and its influence on nucleosynthesis models is demonstrated. We find the $^{39}$K(p,$\gamma$)$^{40}$Ca reaction cross section should be the focus of future experimental study to help constrain models aimed at explaining the magnesium-potassium anti-correlation in globular clusters.