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arXiv · 1504.04456

Theoretical neutron-capture cross sections for r-process nucleosynthesis in the $^{48}$Ca region

T. Rauscher·W. Böhmer·K. -L. Kratz·W. Balogh·H. Oberhummer
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Abstract

We calculate neutron capture cross sections for r-process nucleosynthesis in the $^{48}$Ca region, namely for the isotopes $^{40-44}$S, $^{46-50}$Ar, $^{56-66}$Ti, $^{62-68}$Cr, and $^{72-76}$Fe. While previously only cross sections resulting from the compound nucleus reaction mechanism (Hauser-Feshbach) have been considered, we recalculate not only that contribution to the cross section but also include direct capture on even-even nuclei. The level schemes, which are of utmost importance in the direct capture calculations, are taken from quasi-particle states obtained with a folded-Yukawa potential and Lipkin-Nogami pairing. Most recent deformation values derived from experimental data on $\beta$-decay half lives are used where available. Due to the consideration of direct capture, the capture rates are enhanced and the "turning points" in the r-process path are shifted to slightly higher mass numbers. We also discuss the sensitivity of the direct capture cross sections on the assumed deformation.

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T. Rauscher, W. Böhmer, K. -L. Kratz, W. Balogh, H. Oberhummer. 2015-04-17. Theoretical neutron-capture cross sections for r-process nucleosynthesis in the $^{48}$Ca region. https://arxiv.org/abs/1504.04456

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