The Investigation of the 8Li(α, n)11B Cross Section at Low Energy by a Distorted Wave Born Approximation Model.

The investigation of the cross section of the ⁸Li(α, n)¹¹B reaction has vital importance for both primordial nucleosynthesis in inhomogeneous models and constraining the physical conditions characterizing the r-process. In order to understand the reaction mechanism at low energies, we have applied the Distorted Wave Born Approximation (DWBA) theory below 2 MeV to determine direct reaction contribution. The total cross section has been calculated for the transitions of excited states to ⁸Li(α, n)¹¹B. Spectroscopic factor strengths for ⁸Li(α, n)¹¹B have been calculated within the framework of the shell model. Furthermore, the existing experimental measurements concerning the reaction in question at Big Bang zone and r-process region were analyzed using Wentzel, Kramers and Brilloin method (WKB) and distorted wave born approximation methods respectively. However, both resonance-like structures of ¹²B at low energies and unclear nuclear structure of ⁸Li strongly influence total cross section in the Big Bang and r-process zones. It is apparent that reaction mechanism of ⁸Li(α, n)¹¹B is out of the scope DWBA and WKB. Furthermore, in order to understand reaction mechanisms at low energies, a new experimental setup is proposed for measuring the angular distributions and total cross-section for ⁸Li(α, n)¹¹B. [ABSTRACT FROM AUTHOR]