Measurement of the^2H(^7Be,^6Li)^3He reaction rate and its contribution to the primordial lithium abundance  

作　　者：Er-Tao Li Zhi-Hong Li Sheng-Quan Yan Jun Su Bing Guo Yun-Ju Li You-Bao Wang Gang Lian Sheng Zeng Si-Zhe Chen Shao-Bo Ma Xiang-Qing Li Cao He Hui-Bin Sun Wei-Ping Liu 李二涛;李志宏;颜胜权;苏俊;郭冰;李云居;王友宝;连钢;曾晟;陈思泽;马少波;李湘庆;何超;孙慧斌;柳卫平(China Institute of Atomic Energy, Beijing 102413, China;College of Physics and Energy, Shenzhen University, Shenzhen 518060, China;Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China;School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China)

机构地区：[1]China Institute of Atomic Energy,Beijing 102413,China [2]College of Physics and Energy,Shenzhen University,Shenzhen 518060,China [3]Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China [4]School of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University,Beijing 100871,China

出　　处：《Chinese Physics C》2018年第4期150-156,共7页中国物理C（英文版）

基　　金：Supported by National Natural Science Foundation of China(11375269,11505117,11490560,11475264,11321064);Natural Science Foundation of Guangdong Province(2015A030310012);973 program of China(2013CB834406);National key Research and Development Province(2016YFA0400502)

摘　　要：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.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.

关 键 词：reaction rates primordial lithium abundance big bang nucleosynthesis lithium puzzles 

分 类 号：O571[理学—粒子物理与原子核物理]