Light-Element Reaction Flow and the Conditions for r-Process Nucleosynthesis

Abstract

We deduce new constraints on the entropy per baryon ($s/k$), dynamical timescale (${\tau }_{dyn}$), and electron fraction ($Y_e$) consistent with heavy element nucleosynthesis in the r-process. We show that the previously neglected reaction flow throu gh the reaction sequence \atg (n,$\gamma$)\Li~ significantly enhances the production of seed nuclei. We analyze the r-process nucleosynthesis in the context of a schematic exponential wi nd 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 two higher than previous estimates. This places new constraints on dynamical mo dels for the r-process.

submitted to ApJ, 14pages, 2figures

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Cited by in corpus (5)

• Proto-Neutron Star Winds with Magnetic Fields and Rotation
• Frontiers in Nuclear Astrophysics
• Have Superheavy Elements been Produced in Nature?
• Cross Section Measurement of 9Be(γ,n)8Be and Implications for α+α+n -> 9Be in the r-Process
• Solving the large discrepancy between inclusive and exclusive measurements of the ${}^8\mathrm{Li}+{}^4\mathrm{He}\to {}^{11}\mathrm{B}+n$ reaction cross section at astrophysical energies