1. Constraining the $^{30}$P($p,\gamma)^{31}$S reaction rate in ONe novae via the weak, low-energy, $\beta$-delayed proton decay of $^{31}$Cl
- Author
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Budner, T., Friedman, M., Wrede, C., Brown, B. A., José, J., Pérez-Loureiro, D., Sun, L. J., Surbrook, J., Ayyad, Y., Bardayan, D. W., Chae, K., Chen, A. A., Chipps, K. A., Cortesi, M., Glassman, B., Hall, M. R., Janasik, M., Liang, J., O'Malley, P., Pollacco, E., Psaltis, A., Stomps, J., and Wheeler, T.
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Nuclear Experiment ,Nuclear Theory - Abstract
The $^{30}$P$(p,\gamma)^{31}$S reaction plays an important role in understanding nucleosynthesis of $A\geq 30$ nuclides in oxygen-neon novae. The Gaseous Detector with Germanium Tagging was used to measure $^{31}$Cl $\beta$-delayed proton decay through the key $J^{\pi}=3/2^{+}$, 260-keV resonance. The intensity $I^{260}_{\beta p} = 8.3^{+1.2}_{-0.9} \times 10^{-6}$ represents the weakest $\beta$-delayed, charged-particle emission ever measured below 400 keV, resulting in a proton branching ratio of $\Gamma_p / \Gamma = 2.5^{+0.4}_{-0.3} \times 10^{-4}$. By combining this measurement with shell-model calculations for $\Gamma_{\gamma}$ and past work on other resonances, the total $^{30}$P$(p,\gamma)^{31}$S rate has been determined with reduced uncertainty. The new rate has been used in hydrodynamic simulations to model the composition of nova ejecta, leading to a concrete prediction of $^{30}$Si/$^{28}$Si excesses in presolar nova grains and the calibration of nuclear thermometers., Comment: 7 pages, 2 figures, accepted to Physical Review Letters on April 4, 2022
- Published
- 2022
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