QED corrections to the big-bang nucleosynthesis reaction rates

Understand

We compute radiative corrections to nuclear reaction rates that determine the outcome of the Big-Bang Nucleosynthesis (BBN).

• Any nuclear reaction producing a photon with an energy above $2m_e$ must be supplemented by the corresponding reaction where the final state photon is replaced by an electron-positron pair.
• We find that pair production brings a typical $0.2 \%$ enhancement to photon emission rates, resulting in a similar size corrections to elemental abundances.
• The exception is $^4{\rm He}$ abundance, which is insensitive to the small changes in the nuclear reaction rates.