Probing the $^{12}$C+$^{12}$C fusion reaction via zero-degree spectator measurement in the $^{12}$C($^{14}$N,$αd$)$^{20}$Ne quasi-free reaction

Abstract

The 12C+12C fusion reaction is a key physical process in stellar evolution and supernova explosions. It not only determines the late evolutionary fate of massive stars but also directly influences the critical conditions for triggering Type Ia supernovae in accreting white dwarfs. In this work, the THM was employed to investigate the 12C(12C,a0)20Ne reaction channel of the 12C+12C fusion process, using 14N as the Trojan horse nucleus. Telescope detectors were placed at 0 and 15 deg. to design two experimental configurations covering the forward-angle regions where spectator particles are most likely to emerge. By applying the DWBA, two sets of astrophysical S*(E) factors for the two-body reaction 12C(12C,a0)20Ne were extracted from the three-body reaction 12C(14N,da0)20Ne and normalized to existing experimental data. The results show that, limited by the overall experimental resolution, the present study cannot resolve fine resonance structures. Within the astrophysical energy region of 0.5-2 MeV, the extracted S*(E) factor exhibits an increasing trend toward lower energies. The S*(E) factor obtained with the 0-deg configuration shows a flatter trend than that obtained with the 15-deg configuration. Supported by the quasi-free reaction simulation results, the divergence between the two data sets may reflect a combination of experimental acceptance effects, finite detector resolution, and possible differences in the relative contributions of reaction mechanisms. This study provides a systematic examination of the experimental design, quasi-free event selection strategy, and interpretation of the underlying physical mechanisms, serving as a useful reference for understanding the role of the 12C+12C fusion reaction in astrophysical processes.