Excitation function for theLi6+αreaction between 0.5 and 1.4 MeV

Abstract

The recent discovery of carbon enhanced metal poor (CEMP) stars leaves open questions as to how carbon, nitrogen, and oxygen (CNO) elements were enriched through the nucleosynthesis of primordial elements in the first stars. It has been proposed that the reaction sequence $^{6}\mathrm{Li}(\ensuremath{\alpha},\ensuremath{\gamma})^{10}\mathrm{B}(\ensuremath{\alpha},d)^{12}\mathrm{C}$ may offer an alternative path to the traditional triple-$\ensuremath{\alpha}$ process, taking advantage of $\ensuremath{\alpha}$ cluster configurations in the $^{10}\mathrm{B}$ and $^{14}\mathrm{N}$ compound nuclei. In the present study, an investigation of the low-energy $^{6}\mathrm{Li}(\ensuremath{\alpha},\ensuremath{\gamma})^{10}\mathrm{B}$ cross section is performed using a combination of different $\ensuremath{\gamma}$ ray detectors. The discrepancies in the literature of the width of the broad resonance (${E}_{\text{c.m.}}=1200$ keV, ${1}_{3}^{+}$) are resolved. A consistent and much more precise width, ${\mathrm{\ensuremath{\Gamma}}}_{\ensuremath{\alpha}}=125(8)$ keV, is obtained via a simultaneous $R$-matrix fit of the data from the present study and that reported previously in the literature. The uncertainty in the tail contribution of the broad resonance indicates that a substantial increase in the low temperature reaction rate is possible compared to that adopted by the REACLIB compilation.