  The WMAP satellite, devoted to the observations of the anisotropies of the
Cosmic Microwave Background (CMB) radiation, has recently provided a
determination of the baryonic density of the Universe with unprecedented
precision. Using this, Big Bang Nucleosynthesis (BBN) calculations predict a
primordial 7Li abundance which is a factor 2-3 higher than that observed in
galactic halo dwarf stars. It has been argued that this discrepancy could be
resolved if the 7Be(d,p)2alpha reaction rate is around a factor of 100 larger
than has previously been considered. We have now studied this reaction, for the
first time at energies appropriate to the Big Bang environment, at the CYCLONE
radioactive beam facility at Louvain-la-Neuve. The cross section was found to
be a factor of 10 smaller than derived from earlier measurements. It is
concluded therefore that nuclear uncertainties cannot explain the discrepancy
between observed and predicted primordial 7Li abundances, and an alternative
astrophysical solution must be investigated.
