Neutrino capture and r-process nucleosynthesis

Abstract

Neutrino capture effects on free nucleons and heavy nuclei in r-process nucleosynthesis are discussed. Neutrino capture on heavy nuclei can “accelerate” the r-process; however, the dominant role neutrino capture plays is to set the neutron-to-proton ratio. In fact, network calculations indicate that neutrino capture on heavy nuclei is unlikely to be significant for r-process components that produce nuclei with mass number A near 195. The reason is that if the neutrino flux is sufficiently large to cause neutrino capture on heavy nuclei to be important, it was even larger in a earlier phase when 4He and neutrons dominated the abundances and capture on the free neutrons drastically reduced the neutron-to-seed-nucleus ratio.