出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The recent observations of non-negligible amounts of 6Li in old halo stars have renewed interest
in the Big-Bang Nucleosynthesis (BBN) of 6Li. The deduced primordial 6Li abundance was
found to be unexpectedly large compared to the BBN predictions. One important ingredient in
the BBN predictions is the low-energy D(a,g )6Li 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 6Li
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(a,g )6Li reaction
using Coulomb dissociation (CD) of 6Li 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 6Li abundance as a function of the baryon-tophoton
ratio.
