Cascade transitions versus cascade transitions in <sup>15</sup>N(p,γ)<sup>16</sup>O at the stellar energy range
ORAL
Abstract
The reaction 15N(p,γ)16O is a branch point in the CNO cycle. Consideration of broad resonances Jπ=1-, 2-,3- in 16O are key points for description of the S-factor and reaction rate for radiative p15N capture at the stellar energy T9<10. We report results for astrophysical low-energy S−factor that includes contributions of the 3S1 resonances due to the E1 transitions and the contribution of M1 transition via 3P1 scattering wave in p + 15N channel [1]. The extrapolated S(0) turned out to be within 34.7 − 40.4 keV·b depending on an asymptotic constant. We estimate the contribution of cascade transitions to the reaction rate based on the exclusive experimental data for the cascade transitions 15N(p,γ(6.050))16O, 15N(p,γ(6.130))16O, 15N(p,γ(7.117))16O. The reaction rate enhancement due to these cascade transitions is observed from T9 > 0.3 and reaches the maximum factor ∼ 1.3 at 1.3T9. Our results obtained based on the experimental partial S-factors contradict to a peculiar enhancement behavior of the ratio reported in NACRE II at 0.4< T9 < 10. The latter calls for a careful theoretical investigation of contributions two interfering resonances 2- at 12.530 MeV and 12.9686 MeV and two interfering resonances 3- at 13.142 MeV and 13.265 MeV.
- S. B. Dubovichenko, N. A. Burkova, R. Ya. Kezerashvili, A. S. Tkachenko, B. M. Yeleusheva, arXiv:2303.14680v2, 2023.
G. Imbriani, et al., Phys. Rev. C 85, 065810; 86,039902(E) (2012).
*This research was supported by the Ministry of Science and Higher Education of the Republic of Kazakhstan under the grant AP09259174.
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Presenters
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Nataliya A Burkova
- al-Farabi Kazakh National University, Kazakhstan