Experimental study of the ${}^{30}$Si(${}^3$He,$d$)${}^{31}$P reaction and thermonuclear reaction rate of ${}^{30}$Si($p$,$\gamma$)${}^{31}$P

Abstract

[Background] Abundance anomalies in some globular clusters, such as the enhancement of potassium and the depletion of magnesium, can be explained in terms of an earlier generation of stars polluting the presently observed ones. It was shown that the potential range of temperatures and densities of the polluting sites depends on the strength of a few number of critical reaction rates. The reaction has been identified as one of these important reactions. [Purpose] The key ingredient for evaluating the thermonuclear reaction rate is the strength of the resonances which, at low energy, are proportional to their proton width. Therefore the goal of this work is to determine the proton widths of unbound 31P states. [Method] States in 31P were studied at the Maier-Leibnitz-Laboratorium using the one-proton transfer reaction. Deuterons were detected with the Q3D magnetic spectrometer. Angular distribution and spectroscopic factors were extracted for 27 states, and proton widths and resonance strengths were calculated for the unbound states. [Results] Several unbound states have been observed for the first time in a one-proton transfer reaction. Above 20 MK, the reaction rate is now entirely estimated from the observed properties of states. The reaction rate uncertainty from all resonances other than the resonance has been reduced down to less than a factor of two above that temperature. The unknown spin and parity of the resonance dominates the uncertainty in the rate in the relevant temperature range. [Conclusion] The remaining source of uncertainty on the reaction rate comes from the unknown spin and parity of the resonance which can change the reaction rate by a factor of ten in the temperature range of interest.

References in corpus (13)

• Multiple populations in globular clusters. Lessons learned from the Milky Way globular clusters
• A Triple Main Sequence in the Globular Cluster NGC 2808
• Properties of stellar generations in Globular Clusters and relations with global parameters
• Charged-Particle Thermonuclear Reaction Rates: I. Monte Carlo Method and Statistical Distributions
• Light nuclei in galactic globular clusters : constraints on the self-enrichment scenario from nucleosynthesis
• The Bizarre Chemical Inventory of NGC 2419, An Extreme Outer Halo Globular Cluster
• Charged-Particle Thermonuclear Reaction Rates: III. Nuclear Physics Input
• Quantum Monte Carlo calculations of spectroscopic overlaps in $A\le 7$ nuclei
• The Relationship Between Globular Cluster Mass, Metallicity, and Light Element Abundance Variations
• The Effects of Variations in Nuclear Interactions on Nucleosynthesis in Thermonuclear Supernovae
• On Potassium and Other Abundance Anomalies of Red Giants in NGC 2419
• Sensitivity to Thermonuclear Reaction Rates in Modeling the Abundance Anomalies of NGC 2419
• Thermonuclear Reaction Rate of ${}^{30}$Si(p,$\gamma$)${}^{31}$P

Cited by in corpus (1)

• The 2025 Evaluation of Experimental Thermonuclear Reaction Rates (ETR25)