Modified astrophysical S-factor of 12C+12C fusion reaction at sub-barrier energies

• 来源期刊: 中国物理C（英文版）
• 年，卷（期）: 2020,（11）
• 所属期刊栏目: PARTICLE AND NUCLEAR ASTROPHYSICS AND COSMOLOGY
• 页码范围: 189-207
• 页数: 19页
• 语种: 英文
• DOI: 10.1088/1674-1137/abae56

摘要

The 12C+12C fusion reaction plays a crucial role in stellar evolution and explosions.Its main open reaction channels include α,p,n,and 8Be.Despite more than a half century of efforts,large differences remain among the ex-perimental data of this reaction measured using various techniques.In this work,we analyze the existing data using a statistical model.Our calculation shows the following:1)the relative systematic uncertainties of the predicted branching ratios decrease as the predicted ratios increase;2)the total modified astrophysical S-factors(S factors)of the p and α channels can be obtained by summing the S factors of their corresponding ground-state transitions and the characteristic y rays,while taking into account the contributions of the missing channels to the latter.After apply-ing corrections based on branching ratios predicted by the statistical model,an agreement is achieved among the dif-ferent data sets at Ecm ＞ 4 MeV,while some discrepancies remain at lower energies,suggesting the need for better measurements in the near future.We find that the S* factor recently obtained from an indirect measurement is incon-sistent with the direct measurement value at energies below 2.6 MeV.We recommend upper and lower limits for the 12C+12C S* factor based on the existing models.A new 12C+12C reaction rate is also recommended.