Abstract
We deduce new constraints on the entropy per baryon (s/k), dynamical timescale (τdyn), and electron fraction (Ye) consistent with heavy-element nucleosynthesis in the r-process. We show that the previously neglected reaction flow through the reaction sequence 4He(t, γ)7Li(n, γ)8Li(α, n)11B significantly enhances the production of seed nuclei. We analyze the r-process nucleosynthesis in the context of a schematic exponential wind model. We show that fewer neutrons per seed nucleus implies that the entropy per baryon required for successful r-process nucleosynthesis must be more than a factor of 2 higher than previous estimates. This places new constraints on dynamical models for the r-process.
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