Abstract
The reaction is critical for AGB star nucleosynthesis due to its connection to the abundances of several key isotopes, such as and . However, the ambiguous resonance energy and spin-parity of the dominant 470 keV resonance leads to substantial uncertainty in the reaction rate for the temperature of interest. We have measured the resonance energies and strengths of the low-energy resonances in at the Jinping Underground Nuclear Astrophysics experimental facility (JUNA) with improved precision. The key 470 keV resonance energy has been measured to be , with such high precision achieved for the first time. The spin-parity of this resonance state is determined to be , removing discrepancies in the resonance strengths in earlier studies. The results significantly improve the precision of the reaction rates by up to about 10 times compared with the previous data at typical AGB temperatures of 0.1–0.3 GK. We demonstrate that such improvement leads to precise abundance predictions, with an impact on probing the origin of meteoritic stardust SiC grains from AGB stars.
- Received 27 June 2022
- Revised 22 September 2022
- Accepted 13 January 2023
DOI:https://doi.org/10.1103/PhysRevLett.130.092701
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