| Autor: |
Hu, J., He, J. J., Parikh, A., Xu, S. W., Yamaguchi, H., Kahl, D., Ma, P., Su, J., Wang, H. W., Nakao, T., Wakabayashi, Y., Teranishi, T., Hahn, K. I., Moon, J. Y., Sung, H. S., Hashimoto, T., Chen, A. A., Irvine, D., Lee, C. S., Kubono, S. |
| Rok vydání: |
2014 |
| Předmět: |
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| Druh dokumentu: |
Working Paper |
| Popis: |
The $^{14}$O($\alpha$,$p$)$^{17}$F reaction is one of the key reactions involved in the breakout from the hot-CNO cycle to the rp-process in type I x-ray bursts. The resonant properties in the compound nucleus $^{18}$Ne have been investigated through resonant elastic scattering of $^{17}$F+$p$. The radioactive $^{17}$F beam was separated by the CNS Radioactive Ion Beam separator (CRIB) and bombarded a thick H$_2$ gas target at 3.6 MeV/nucleon. The recoiling light particles were measured by using three ${\Delta}$E-E silicon telescopes at laboratory angles of $\theta$$_{lab}$$\approx$3$^\circ$, 10$^\circ$ and 18$^\circ$, respectively. Five resonances at $E_{x}$=6.15, 6.28, 6.35, 6.85, and 7.05 MeV were observed in the excitation functions. Based on an $R$-matrix analysis, $J^{\pi}$=1$^-$ was firmly assigned to the 6.15-MeV state. This state dominates the thermonuclear $^{14}$O($\alpha$,$p$)$^{17}$F rate below 1 GK. We have also confirmed the existence and spin-parities of three states between 6.1 and 6.4 MeV. As well, a possible new excited state in $^{18}$Ne was observed at $E_{x}$=6.85$\pm$0.11 MeV and tentatively assigned as $J$=0. This state could be the analog state of the 6.880 MeV (0$^{-}$) level in the mirror nucleus $^{18}$O, or a bandhead state (0$^+$) of the six-particle four-hole (6$p$-4$h$) band. A new thermonuclear rate of the $^{14}$O($\alpha$,$p$)$^{17}$F reaction has been determined, and its astrophysical impact has been examined within the framework of one-zone x-ray burst postprocessing calculations. |
| Databáze: |
arXiv |
| Externí odkaz: |
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