Weak interference between the 1$^-$ states in the vicinity of $\alpha$-particle threshold of $^{16}$O

M. Katsuma

doi:10.1007/978-3-030-13876-9_72

Weak interference between the 1$^-$ states in the vicinity of $\alpha$-particle threshold of $^{16}$O

Nuclear Theory 2020-01-08 v1 Solar and Stellar Astrophysics Nuclear Experiment

Authors: M. Katsuma

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Abstract

The subthreshold 1 $^-_1$ state at an excitation energy $E_x = 7.12$ MeV in $^{16}$ O has been believed to enhance the $S$ -factor of $^{12}$ C( $\alpha$ , $\gamma$ ) $^{16}$ O. The enhancement seems to originate from strong interference between 1 $^-_1$ and 1 $^-_2$ ( $E_x\approx 9.6$ MeV) in the vicinity of the $\alpha$ -particle threshold. However, weak interference between them and a resulting small $E$ 1 $S$ -factor are exemplified with $R$ -matrix theory. Including a higher-order correction of the resonance parameters, the present example appears to reproduce the experimental data consistently. It would therefore be possible that the $E$ 1 $S$ -factor is reduced at low energies.

Keywords

r-matrix theory alpha capture interference s-factor o-16 subthreshold state phase shift

Cite

@article{arxiv.1811.10836,
  title  = {Weak interference between the 1$^-$ states in the vicinity of $\alpha$-particle threshold of $^{16}$O},
  author = {M. Katsuma},
  journal= {arXiv preprint arXiv:1811.10836},
  year   = {2020}
}

Comments

3 pages, 1 figure; to appear in "Springer Proceedings in Physics", Proc. of Nuclei in the Cosmos XV, LNGS Assergi, Italy, 24-29 June 2018

Weak interference between the 1$^-$ states in the vicinity of $\alpha$-particle threshold of $^{16}$O

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