Portillo, F., Longland, R., Cooper, A. L. et al. (4 more authors) (2023) Spin-parities of sub-threshold resonances in the $^{18}$F(p, $α$)$^{15}$O reaction. [Preprint]
Abstract
The $^{18}$F(p, $\alpha$)$^{15}$O reaction is key to determining the $^{18}$F abundance in classical novae. However, the cross section for this reaction has large uncertainties at low energies largely caused by interference effects. Here, we resolve a longstanding issue with unknown spin-parities of sub-threshold states in $^{19}$Ne that reduces these uncertainties. The $^{20}$Ne($^3$He, $^4$He)$^{19}$Ne neutron pick-up reaction was used to populate $^{19}$Ne excited states, focusing on the energy region of astrophysical interest ($\approx$ 6 - 7 MeV). The experiment was performed at the Triangle Universities Nuclear Laboratory using the high resolution Enge split-pole magnetic spectrograph. Spins and parities were found for states in the astrophysical energy range. In particular, the state at 6.133 MeV (E$_{r}^{\text{c.m.}} = -278$ keV) was found to have spin and parity of $3/2^+$ and we confirm the existence of an unresolved doublet close to 6.288 MeV (E$_{r}^{\text{c.m.}} = -120$ keV) with J$^{\pi}$ = $1/2^+$ and a high-spin state. Using these results, we demonstrate a significant factor of two decrease in the reaction rate uncertainties at nova temperatures.
Metadata
Item Type: | Preprint |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | 15 pages, 6 figures, accepted in Phys. Rev. C |
Keywords: | nucl-ex |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Social Sciences (York) > Sociology (York) The University of York > Faculty of Sciences (York) > Physics (York) The University of York > Faculty of Sciences (York) |
Depositing User: | Pure (York) |
Date Deposited: | 08 Jun 2023 23:19 |
Last Modified: | 09 Feb 2025 00:04 |
Status: | Published |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:200255 |