Effect of Finite Nucleon Mass on Primordial Nucleosynthesis

Abstract

We have modified the standard code for primordial nucleosynthesis to include the effect of finite nucleon mass on the weak-interaction rates as calculated by Seckel \cite{seckel}. We find a small, systematic increase in the ${}^4$He yield, $\Delta Y\simeq 0.0057Y$, which is insensitive to the value of the baryon-to-photon ratio $\eta$ and slightly larger than Seckel's estimate. The fractional changes in the abundances of D, ${}^3$He, and ${}^7$Li range from 0.08\% to 3\% for $10^{-11}\le \eta \le 10^{-8}$.

Comments: 10 pages, 2 Figs available on request, FERMILAB-Pub-93/181-A