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Improved Direct Measurement of the 64.5 keV Resonance Strength in the 17O(p,a)14N Reaction at LUNA
- Source :
- Physics Review Letters, 117, 142502 (2016)
- Publication Year :
- 2016
-
Abstract
- The $^{17}$O(p,$\alpha$)$^{14}$N reaction plays a key role in various astrophysical scenarios, from asymptotic giant branch stars to classical novae. It affects the synthesis of rare isotopes such as $^{17}$O and $^{18}$F, which can provide constraints on astrophysical models. A new direct determination of the $E_{\rm R}~=~64.5$~keV resonance strength performed at the Laboratory for Underground Nuclear Astrophysics accelerator has led to the most accurate value to date, $\omega\gamma = 10.0 \pm 1.4_{\rm stat} \pm 0.7_{\rm syst}$~neV, thanks to a significant background reduction underground and generally improved experimental conditions. The (bare) proton partial width of the corresponding state at $E_{\rm x} = 5672$~keV in $^{18}$F is $\Gamma_{\rm p} = 35 \pm 5_{\rm stat} \pm 3_{\rm syst}$~neV. This width is about a factor of 2 higher than previously estimated thus leading to a factor of 2 increase in the $^{17}$O(p,$\alpha$)$^{14}$N reaction rate at astrophysical temperatures relevant to shell hydrogen-burning in red giant and asymptotic giant branch stars. The new rate implies lower $^{17}$O/$^{16}$O ratios, with important implications on the interpretation of astrophysical observables from these stars.
- Subjects :
- Nuclear Experiment
Subjects
Details
- Database :
- arXiv
- Journal :
- Physics Review Letters, 117, 142502 (2016)
- Publication Type :
- Report
- Accession number :
- edsarx.1610.00483
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevLett.117.142502