학술논문
Constraining the $^{12}$C+$^{12}$C astrophysical S-factors with the $^{12}$C+$^{13}$C measurements at very low energies
Document Type
Working Paper
Author
Zhang, N. T.; Wang, X. Y.; Chen, H.; Chen, Z. J.; Lin, W. P.; Xin, W. Y.; Xu, S. W.; Tudor, D.; Chilug, A. I.; Stefanescu, I. C.; Straticiuc, M.; Burducea, I.; Ghita, D. G.; Margineanu, R.; Gomoiu, C.; Pantelica, A.; Chesneanu, D.; Trache, L.; Tang, X. D.; Bucher, B.; Gasques, L. R.; Hagino, K.; Kubono, S.; Li, Y. J.; Lin, C. J.; Umar, A. S.; Xu, Y.
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Subject
Language
Abstract
We use an underground counting lab with an extremely low background to perform an activity measurement for the $^{12}$C+$^{13}$C system with energies down to $E\rm_{c.m.}$=2.323 MeV, at which the $^{12}$C($^{13}$C,$p$)$^{24}$Na cross section is found to be 0.22(7) nb. The $^{12}$C+$^{13}$C fusion cross section is derived with a statistical model calibrated using experimental data. Our new result of the $^{12}$C+$^{13}$C fusion cross section is the first decisive evidence in the carbon isotope systems which rules out the existence of the astrophysical S-factor maximum predicted by the phenomenological hindrance model, while confirming the rising trend of the S-factor towards lower energies predicted by other models, such as CC-M3Y+Rep, DC-TDHF, KNS, SPP and ESW. After normalizing the model predictions with our data, a more reliable upper limit is established for the $^{12}$C+$^{12}$C fusion cross sections at stellar energies.