New measurement of the cross section of the big bang nucleosynthesis reaction D(a,g)6Li and its astrophysical impact
Abstract
The recent observations of non-negligible amounts of 6 Li in old halo stars have renewed interest in the Big-Bang Nucleosynthesis (BBN) of 6 Li. The deduced primordial 6 Li abundance was found to be unexpectedly large compared to the BBN predictions. One important ingredient in the BBN predictions is the low-energy D(α,γ)6 Li cross section. Up to now, the only available experimental result for this cross section introduced an error of about a factor of 20 in the 6 Li abundance at the energies of astrophysical interest (Ecm ≤ 300 keV). This uncertainty arises from the discrepancy between the theoretical low energy dependence of the S-factor and the experimental data. Accordingly, new measurements of the cross section of the D(α,γ) 6 Li reaction using Coulomb dissociation (CD) of 6 Li at 150 A MeV have been performed recently at GSI. The preliminary GSI results, which indicate a drop of the S-factor as predicted by theory will be presented as well their impact on the calculated 6 Li abundance as a function of the baryon-to- photon ratio.
- Publication:
-
International Symposium on Nuclear Astrophysics - Nuclei in the Cosmos
- Pub Date:
- 2006
- DOI:
- 10.22323/1.028.0013
- Bibcode:
- 2006isna.confE..13H