Thermonuclear Reaction Rate of ${}^{30}$Si(p,$\gamma$)${}^{31}$P

Abstract

Silicon synthesis in high-temperature hydrogen burning environments presents one possible avenue for the study of abundance anomalies in globular clusters. This was suggested in a previous study, which found that the large uncertainties associated with the ${}^{30}$Si(p,$\gamma$)${}^{31}$P reaction rate preclude a firm understanding of the stellar conditions that give rise to the Mg-K anti-correlation observed in the globular cluster NGC 2419. In an effort to improve the reaction rate, we present new strength measurements of the $E_r^{lab}=435$ keV and $E_r^{lab}=501$ keV resonances in ${}^{30}$Si(p,$\gamma$)${}^{31}$P. For the former, which was previously unobserved, we obtain a resonance strength of $\omega \gamma =(1.28\pm 0.25$) $\times 10^{-4}$ eV. For the latter, we obtain a value of $\omega \gamma =(1.88\pm 0.14)$ $\times 10^{-1}$ eV, which has a smaller uncertainty compared to previously measured strengths. Based on these results, the thermonuclear reaction rate has been re-evaluated. The impact of the new measurements is to lower the reaction rate by a factor of $\approx$10 at temperatures important to the study of NGC 2419. The rate uncertainty at these temperatures has also been reduced significantly.

27 pages, 7 figures

References in corpus (4)

• The Bizarre Chemical Inventory of NGC 2419, An Extreme Outer Halo Globular Cluster
• Sensitivity to Thermonuclear Reaction Rates in Modeling the Abundance Anomalies of NGC 2419
• $\gamma$-ray Spectroscopy using a Binned Likelihood Approach
• Calculation of resonance energies from Q-values

Cited by in corpus (5)

• Horizons: Nuclear Astrophysics in the 2020s and Beyond
• The Status and Future of Direct Nuclear Reaction Measurements for Stellar Burning
• Thermonuclear reaction rate of ${}^{29}$Si(p,$\gamma$)${}^{30}$P
• Experimental study of the ${}^{30}$Si(${}^3$He,$d$)${}^{31}$P reaction and thermonuclear reaction rate of ${}^{30}$Si($p$,$\gamma$)${}^{31}$P
• The 2025 Evaluation of Experimental Thermonuclear Reaction Rates (ETR25)