Radiative 3He(2H,γ)5Li Capture at Astrophysical Energy and Its Possible Role in Accumulation of 6Li at the BBN

Abstract

Big Bang Nucleosynthesis (BBN) relevance reactions 3 He( 2 H,γ) 5 Li, 3 H( 3 He,γ) 6 Li, 5 Li(n,γ) 6 Li as a key to approach for scenario of 6 Li formation are treated. The rates of reaction for these processes are analyzed. Comparison of the reactions rates and the prevalence of light elements leads to the assumption that the two-step process 2 H + 3 He  5 Li +  and n + 5 Li  6 Li +  can make a significant contribution to the formation of 6 Li at the BBN at least at temperatures T 9 of the order of unity.Calculations of the total cross sections, astrophysical S-factor, and reaction rates have been performed for 3 He( 2 H,γ) 5 Li radiative capture within the modified potential cluster model with forbidden states, which follow from the classification of the orbital cluster states according to Young diagrams. Numerical data and corresponding parametrizations cover the energy range up to 5 MeV and temperature range T 9 <10. An updated compilation of detailed data for the reaction 3 He( 2 H,γ) 5 Li are presented.Let us now examine in more detail the various aspects of the 3 He( 2 H, γ) 5 Li reaction, including the experimental data presented in the data base (EXFOR, 2013) and the original references cited therein, and the role of this process in various fields of application. Nuclear astrophysics aspectsOur parametrization of the experimental data for 2 H capture in 3 He (Buss et al. 1968) for the Sfactor at energies from 0.2 to 1.0 MeV according to Breit-Wigner and its further extrapolation 8 ) , ( J J I J J NJ P K NJ A J J J J J J J J