Revised Uncertainties in Big Bang Nucleosynthesis

Abstract

Big Bang Nucleosynthesis (BBN) explores the first few minutes of nuclei formation after the Big Bang. We present updates that result in new constraints at the 2σ level for the abundances of the four primary light nuclides - D,3He,4He, and 7Li - in BBN. A modified standard BBN code was used in a Monte Carlo analysis of the nucleosynthesis uncertainty as a function of baryon-to-photon ratio. Reaction rates were updated to those of NACRE and REACLIB, and R-Matrix calculations. The results are then used to derive a new constraint on the effective number of neutrinos.