R-matrix analysis of reactions in the 9B compound system applied to the 7Li problem in BBN

6th Nuclear Physics in Astrophysics

物理学;天文学

Paris, M.^1 ; Hale, G.^1 ; Hayes-Sterbenz, A.^1 ; Jungman, G.^1

T-2 Nuclear and Particle Physics, Astrophysics and Cosmology, Los Alamos National Laboratory, Los Alamos

NM

87545, United States^1

关键词: Big bang nucleosynthesis;    Compound system;    Differential cross section;    Integrated cross sections;    Integrated reactions;    R-matrix analysis;    Resonance enhanced;    Resonance parameters;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/665/1/012006/pdf
DOI  :  10.1088/1742-6596/665/1/012006

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

Recent activity in solving the 'lithium problem' in big bang nucleosynthesis has focused on the role that putative resonances may play in resonance-enhanced destruction of7Li. Particular attention has been paid to the reactions involving the9B compound nuclear system, d+7Be →9B. These reactions are analyzed via the multichannel, two-body unitary R-matrix method using the code EDA developed by Hale and collaborators. We employ much of the known elastic and reaction data, in a four-channel treatment. The data include elastic3He +6Li differential cross sections from 0.7 to 2.0 MeV, integrated reaction cross sections for energies from 0.7 to 5.0 MeV for6Li(3He,p)8Be∗and from 0.4 to 5.0 MeV for the6Li(3He,d)7Be reaction. Capture data have been added to an earlier analysis with integrated cross section measurements from 0.7 to 0.825 MeV for6Li(3He,γ)9B. The resulting resonance parameters are compared with tabulated values, and previously unidentified resonances are noted. Our results show that there are no near d+7Be threshold resonances with widths that are 10's of keV and reduce the likelihood that a resonance-enhanced mass-7 destruction mechanism, as suggested in recently published work, can explain the7Li problem.