Measurement of the cross section for the 4He(α, n)7Be reaction as a possible solution to the cosmological lithium problem

11th International Conference on Clustering Aspects of Nuclear Structure and Dynamics

Kawabata, T.^1 ; Furuno, T.^1 ; Ichikawa, M.^1 ; Iwasa, N.^2 ; Kanada-En'Yo, Y.^1 ; Koshikawa, A.^1 ; Kubono, S.^3 ; Miyawaki, E.^1 ; Morimoto, T.^1 ; Murata, M.^1 ; Nanamura, T.^1 ; Nishimura, S.^3 ; Shikata, Y.^1 ; Takahashi, Y.^1 ; Takeda, T.^1 ; Tsumura, M.^1 ; Watanabe, K.^1

Department of Physics, Kyoto University, Sakyo, Kyoto

606-8502, Japan^1

Department of Physics, Tohoku University, Aoba, Miyagi, Sendai

980-8578, Japan^2

RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama

351-0198, Japan^3

关键词: Big bang nucleosynthesis;    Detailed balance;    Energy windows;    Theoretical estimation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/863/1/012073/pdf
DOI  :  10.1088/1742-6596/863/1/012073

来源: IOP

【 摘 要 】

The cross section for the4He(α,n)7Be reaction was measured at low energies between Eα= 38.50 and 39.64 MeV motivated by the cosmological lithium problem. On the basis of the detailed balance principle, the cross section for the7Be(n,α)4He reaction was obtained at Ec.m.= 0.20-0.81 MeV close to the Big Bang nucleosynthesis (BBN) energy window for the first time. The obtained cross sections are significantly smaller than the theoretical estimation widely used in the BBN calculations. The present results suggest the7Be(n,α)4He reaction rate is not large enough to solve the cosmological lithium problem.