An Alternative 3α Process: The ²H(α,γ) ⁶Li(α,γ) ¹⁰B(α,d) 12C Reaction in Primordial Stars

The recent discovery of very old Carbon Enhanced Metal Poor (CEMP) stars has left questions as to their origins, in particular with respect to the origin of CNO element production in the early universe. The present research aims to investigate the ²H(α,γ) ⁶Li(α,γ) ¹⁰B(α,d)12C reaction chain, which may prove to be key in answering this question. The ⁶Li(α,γ) and ¹⁰B(α,d) reactions are studied here with some considerations of the ¹⁰B(α,p) channel. These measurements were conducted at the Nuclear Science Laboratory (NSL) at the University of Notre Dame du lac. The ¹⁰B + α reactions were studied using silicon surface barrier detectors in close geometry, whereas the ⁶Li + α reaction used a combination of Cerium Tribromide and High-Purity Germanium detectors. R-Matrix analyses were performed using the AZURE2 code and fits are presented in the text. Presently, a large boost to the ¹⁰B + α reactions is seen at T = 0.1 GK and more accurate broad resonance contributions have been determined for the ⁶Li + α reaction.