Bayesian estimation of the S factor and thermonuclear reaction rate for 16O(p ,γ )17F
Abstract
The 16O(p ,γ )17F reaction is the slowest hydrogen-burning process in the CNO mass region. Its thermonuclear rate sensitively impacts predictions of oxygen isotopic ratios in a number of astrophysical sites, including AGB stars. The reaction has been measured several times at low bombarding energies using a variety of techniques. The most recent evaluated experimental rates have a reported uncertainty of about 7.5% below 1 GK. However, the previous rate estimate represents a best guess only and was not based on rigorous statistical methods. We apply a Bayesian model to fit all reliable 16O(p ,γ )17F cross section data, and take into account independent contributions of statistical and systematic uncertainties. The nuclear reaction model employed is a single-particle potential model involving a Woods-Saxon potential for generating the radial bound state wave function. The model has three physical parameters, the radius and diffuseness of the Woods-Saxon potential, and the asymptotic normalization coefficients (ANCs) of the final bound state in 17F. We find that performing the Bayesian S -factor fit using ANCs as scaling parameters has a distinct advantage over adopting spectroscopic factors instead. Based on these results, we present the first statistically rigorous estimation of experimental 16O(p ,γ )17F reaction rates, with uncertainties (±4.2 %) of about half the previously reported values.
- Publication:
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Physical Review C
- Pub Date:
- November 2022
- DOI:
- 10.1103/PhysRevC.106.055802
- arXiv:
- arXiv:2210.14354
- Bibcode:
- 2022PhRvC.106e5802I
- Keywords:
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- Nuclear Theory;
- Astrophysics - Solar and Stellar Astrophysics;
- Nuclear Experiment
- E-Print:
- 3 figures