Speaker
Description
The astrophysical S-factor and reaction rate of the direct capture process $\alpha+d \rightarrow {}^6{\rm Li} + \gamma$, as well as the abundance of the 6Li element are estimated in a three-body model. The initial state is factorized into the deuteron bound state and the $\alpha+d$ scattering state. The final nucleus $^6$Li(1+) is described as a three-body bound state $\alpha+ n + p$ in the hyperspherical Lagrange-mesh method. Corrections to the asymptotics of the overlap integral in the $S$- and $D$-waves have been done for the E2 S factor. The isospin forbidden $E1$ S-factor is calculated from the initial isosinglet states to the small isotriplet components of the final $^6$Li(1+) bound state. It is shown that the three-body model is able to reproduce the newest experimental data of the LUNA collaboration for the astrophysical S-factor and the reaction rates within the experimental error bars. The estimated $^6$Li/H abundance ratio of (0.67 ± 0.01) × 10−14 is in a very good agreement with the recent measurement (0.80 ± 0.18) × 10−14 of the LUNA collaboration.
