New measurement of the ~8Li(α,n)~(11)B reaction in a lower-energy region below the Coulomb barrier

摘要

The ~8Li(α,n)~(11)Breaction is regarded as the key reaction in the inhomogeneous big bang and in type-Ⅱ supernova nucleosynthesis. Recently, the importance of this reaction to solving the ~7Li problem, i.e., the inconsistency between the predicted and the observed primordial ~7Li abundances, has also been noted. The most recent cross-section data published by our collaboration group in 2006 [H. Ishiyama et al., Phys. Lett. B 640, 82 (2006)] cover the 0.7- to 2.6-MeV energy region in the center-of-mass system. Here, we present additional data spanning the 0.45- to 1.8-MeV energy region. Thus, the predominant energy region for the big bang nucleosynthesis, corresponding to T_9 = 1 (where T_9 is a temperature unit equivalent to 10~9 K), is almost completely spanned by the previous [H. Ishiyama et al., Phys. Lett. B 640, 82 (2006)] and present results together.