Big bang nucleosynthesis: an accurate determination of light element yields

We report the results of a new accurate evaluation of light nuclei yields i n primordial nucleosynthesis. All radiative effects, finite nucleon mass, t hermal and plasma corrections are included in the proton to neutron convers ion rates. The relic densities of He-4, D and Li-7 have been numerically ob tained via a new updated Version of the standard BBN code. In particular th e theoretical uncertainty on He-4 is reduced to the order of 0.1%. (C) 2000 Elsevier Science B.V. All rights reserved.