Speaker
Description
The $^{13}$C($\alpha,$n$)^{16}$O reaction is the primary neutron source for the stellar slow neutron-capture (s-) process and also plays an important role in intermediate (i-) process nucleosynthesis. Due to the extremely small cross sections at astrophysical energies and the overwhelming cosmic-ray–induced background in surface laboratories, direct measurements remain highly challenging. Recent underground measurements performed by the Jinping Underground Nuclear Astrophysics collaboration (JUNA) and the Laboratory for Underground Nuclear Astrophysics collaborations (LUNA) covered nearly the entire i-process Gamow window and reached the edge of the s-process Gamow window. These measurements, together with newly available differential cross-section measurements from the University of Notre Dame, substantially reduced the experimental uncertainty in the astrophysical energy region and provided new constraints for reaction-rate evaluations.
In this work, we present a comprehensive Bayesian-refined R-matrix analysis of the $^{13}$C($\alpha,$n$)^{16}$O reaction by simultaneously incorporating all currently available experimental data. Particular attention is given to the subthreshold resonances, whose interference pattern and reduced width strongly influence the low-energy extrapolation of the reaction cross section. Based on the updated reaction rate, we further investigate its astrophysical impact through asymptotic giant branch (AGB) stellar models by comparing nucleosynthesis predictions obtained with different reaction rates.