New measurement of the Li8(α,n)B11 reaction in a lower-energy region below the Coulomb barrier

The $^{8}\mathrm{Li}(\ensuremath{\alpha},n)^{11}\mathrm{B}$ reaction 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 $^{7}\mathrm{Li}$ problem, i.e., the inconsistency between the predicted and the observed primordial $^{7}\mathrm{Li}$ 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.