Additional production of deuterium and helium-3 by high-energy protons and antiprotons in the early Universe

The results of calculations of ³He, ³H, and D production as a result of the disintegration of primordial ⁴He by high-energy protons and anti-protons in the early Universe are reported. It is shown that for primary particle energies E _p , _p ^t- <0.2 GeV the main role in ³He, ³H, and D production is played by the secondary proton cascade that develops in the cosmological plasma and which destroys ⁴He most intensively at E~75 MeV. At the current state of the experimental data one can calculate the number of nuclei produced to within 10%, and investigation of the inelastic p ⁴He interaction channels at E~75 MeV will make it possible to improve substantially the accuracy of calculations of the additional production of light elements. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 9, 609–613 (May 1999)