Effect of finite nucleon mass on primordial nucleosynthesis

Robert E. Lopez, Michael S. Turner, Geza Gyuk
1997 Physical Review D, Particles and fields  
We have calculated the small effect of finite nucleon mass on the weak-interaction rates that interconvert protons and neutrons in the early Universe. We have modified the standard code for primordial nucleosynthesis to include these corrections and find a small, systematic increase in the 4He yield, δ Y / Y ≃ (0.47 - 0.50) baryon-to-photon ratio. The fractional changes in the abundances of the other light elements are a few percent or less for interesting values of the baryon-to-photon ratio.
doi:10.1103/physrevd.56.3191 fatcat:zlmziqbqyraldanz6q24efsfoy