Nuclear reaction rates and primordial Li-6

We examine the possibility that big-bang nucleosynthesis (BBN) may produce nontrivial amounts of Li-6. If a primordial component of this isotope could be observed, it would provide a new fundamental test of big-bang cosmology, as well as new constraints on the baryon density of the universe. At present, however, theoretical predictions of the primordial Li-6 abundance are extremely uncertain due to difficulties in both theoretical estimates and experimental determinations of the H-2(alpha, gamma)Li-6 radiative capture reaction cross section. We also argue that present observational capabilities do not yet allow the detection of primeval Li-6 in very metal-poor stars of the galactic halo. However, if the critical cross section is very high in its plausible range and the baryon density is relatively low, then improvements in Li-6 detection capabilities may anew the establishment of Li-6 as another product of BBN. It is also doted that a primordial Li-6 detection could help resolve current concerns about the extragalactic D/H determination.