Big Bang Nucleosynthesis represents perhaps the first, and still perhaps the most powerful particle-astrophysics connection. As such, it should provide an example for other work in this area. I discuss the current status of standard model BBN predictions and constraints, and then argue that the issue of observational systematic uncertainties is the key feature limiting our ability to constrain theory with observation. Nevertheless, several very important constraints are currently obtainable. For example, assuming maximal systematic uncertainties in 4He, D, and 7Li we find a conservative upper limit of ΩB ≤ 0.16 in order for BBN predictions to agree with observations. Equally significant, we find that BBN predictions are inconsistent unless 4He abundance by mass is greater than 23.9%, or D +3He estimates are incorrect. By contrast, unless systematic uncertainties are taken into account, the quoted 2σ observational upper limit on the primordial 4He fraction is 23.8%.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics