Higher D or Li: Probes of Physics beyond the Standard Model
  Standard Big Bang Nucleosynthesis at the baryon density determined by the
microwave anisotropy spectrum predicts an excess of \li7 compared to
observations by a factor of 4-5. In contrast, BBN predictions for D/H are
somewhat below (but within ~2 \sigma) of the weighted mean of observationally
determined values from quasar absorption systems. Solutions to the \li7 problem
which alter the nuclear processes during or subsequent to BBN, often lead to a
significant increase in the deuterium abundance consistent with the highest
values of D/H seen in absorption systems. Furthermore, the observed D/H
abundances show considerable dispersion. Here, we argue that those systems with
D/H \simeq 4 \times 10^{-5} may be more representative of the primordial
abundance and as a consequence, those systems with lower D/H would necessarily
have been subject to local processes of deuterium destruction. This can be
accounted for by models of cosmic chemical evolution able to destroy in situ
Deuterium due to the fragility of this isotope.
