Measurement of the 2H(7Be, 6Li)3He reaction rate and its contribution to the primordial lithium abundance
Measurement of the 2H(7Be, 6Li)3He reaction rate and its contribution to the primordial lithium abundance
复制标题
2H(7Be, 6Li)3He反应速率的测量及其对原始锂丰度的贡献
DOI：
10.1088/1674-1137/42/4/044001
复制
发表时间：
2018
影响因子：
3.6
通讯作者：
et al.
中科院分区：
文献类型：
--
作者：
Er-Tao Li;Zhi-Hong Li;Sheng-Quan Yan;Jun Su;Bing Guo;et al.
在标准的大爆炸核合成(SBBN)模型中，锂之谜在过去的几十年里引起了人们的强烈兴趣，但仍然没有得到解决。传统上，方法是包括更多流入或流出锂的反应，并研究这些反应的潜在影响，这些反应以前没有考虑到。7Be(d，3He)6Li是一种既产生6Li又破坏7Be的反应，7Be衰变为7Li，从而间接影响7Li。因此，如果反应速度足够快，该反应可以缓解锂的差异。然而，关于7Be(d，3He)6Li反应速率的信息并不多。本文首次测量了7Be次级束流在质心能量ECm=4.0 MeV和6.7 MeV处的7Be(d，3He)6Li反应角分布。首先用TALYS程序计算了7Be(d，3He)6Li反应的激发函数，然后将其归一化到实验数据中，进而推导出其反应速率。用SBBN网络计算了它对~6Li和~7Li丰度的影响。结果表明，7Be(d，3He)6Li反应由于反应速率小，对6Li和7Li的影响很小。因此，本实验排除了7Be(d，3He)6Li反应作为缓解锂离子差异的一种手段。
In the standard Big Bang nucleosynthesis (SBBN) model, the lithium puzzle has attracted intense interest over the past few decades, but still has not been solved. Conventionally, the approach is to include more reactions flowing into or out of lithium, and study the potential effects of those reactions which were not previously considered. 7Be(d, 3He)6Li is a reaction that not only produces 6Li but also destroys 7Be, which decays to 7Li, thereby affecting 7Li indirectly. Therefore, this reaction could alleviate the lithium discrepancy if its reaction rate is sufficiently high. However, there is not much information available about the 7Be(d, 3He)6Li reaction rate. In this work, the angular distributions of the 7Be(d, 3He)6Li reaction are measured at the center of mass energies Ecm = 4.0 MeV and 6.7 MeV with secondary 7Be beams for the first time. The excitation function of the 7Be(d, 3He)6Li reaction is first calculated with the computer code TALYS and then normalized to the experimental data, then its reaction rate is deduced. A SBBN network calculation is performed to investigate its influence on the 6Li and 7Li abundances. The results show that the 7Be(d, 3He)6Li reaction has a minimal effect on 6Li and 7Li because of its small reaction rate. Therefore, the 7Be(d, 3He)6Li reaction is ruled out by this experiment as a means of alleviating the lithium discrepancy.
DOI：
--
发表时间：
2013
期刊：
--
影响因子：
--
作者：
P. Bogdanovich;R. Kisielius
通讯作者：
P. Bogdanovich;R. Kisielius