Searching for resonance states in ${}^{22}$Ne($p,\gamma$)${}^{23}$Na

Abstract

Background: Globular clusters show strong correlations between different elements, such as the well-known sodium-oxygen anticorrelation. One of the main sources of uncertainty in this anticorrelation is the ${}^{22}$Ne($p,\gamma$)${}^{23}$Na reaction rate, due to the possible influence of an unobserved resonance state at $E_{\mathrm{x}}=8862$ keV ($E_{\mathrm{r},c.m.}=68$ keV). The influence of two higher-lying resonance states at $E_{\mathrm{x}}=8894$ and $9000$ keV has already been ruled out by direct ${}^{22}$Ne($p,\gamma$)${}^{23}$Na measurementsPurpose: To study excited states in ${}^{23}$Na above the proton threshold to determine if the unconfirmed resonance states in ${}^{23}$Na exist. Methods: The non-selective proton inelastic scattering reaction at low energies was used to search for excited states in ${}^{23}$Na above the proton threshold. Protons scattered from various targets were momentum-analysed in the Q3D magnetic spectrograph at the Maier-Leibnitz Laboratorium, Munich, Germany. Results: The resonance states previously reported at $E_{\mathrm{x}}=8862$, $8894$ and $9000$ keV in other experiments were not observed in the present experiment at any angle. This result, combined with other non-observations of these resonance states in most other experiments, results in a strong presumption against the existence of these resonance states. Conclusions: The previously reported resonance states at $E_{\mathrm{x}}=8862$, $8894$ and $9000$ keV are unlikely to exist and should be omitted from future evaluations of the ${}^{22}$Ne($p,\gamma$)${}^{23}$Na reaction rates. Indirect studies using low-energy proton inelastic scattering are a simple and yet exceptionally powerful tool in helping to constrain astrophysical reaction rates by providing non-selective information of the excited states of nuclei.

arXiv comment1 single-panel figure and 5 double-panel figures. Updated version of paper with better organisation of parts

References in corpus (20)

• Fast rotating massive stars and the origin of the abundance patterns in galactic globular clusters
• Multiple Stellar Populations in Globular Clusters
• Predictions for self-pollution in globular cluster stars
• Massive binaries as the source of abundance anomalies in globular clusters
• Evolution, nucleosynthesis and yields of low mass AGB stars at different metallicities (II): the FRUITY database
• Helium variation due to self-pollution among Globular Cluster stars: consequences on the horizontal branch morphology
• Yields of AGB and SAGB models with chemistry of low- and high-metallicity Globular Clusters
• On the self-enrichment scenario of galactic globular clusters: Constraints on the IMF
• The Effects of Thermonuclear Reaction Rate Variations on Nova Nucleosynthesis: A Sensitivity Study
• Super and Massive AGB Stars: II - Nucleosynthesis and Yields - Z=0.02, 0.008 and 0.004
• The Abundance Evolution of Oxygen, Sodium and Magnesium in Extremely Metal-Poor Intermediate Mass Stars: Implications for the Self-Polution Scenario in Globular Clusters
• Fluorine and Sodium in C-rich low-metallicity stars
• Three new low-energy resonances in the ${}^{22}$Ne(p,$\gamma$)${}^{23}$Na reaction
• ${}^{22}$Ne and ${}^{23}$Na ejecta from intermediate-mass stars: The impact of the new LUNA rate for ${}^{22}$Ne(p,$\gamma$)${}^{23}$Na
• Direct capture cross section and the $E_p$ = 71 and 105 keV resonances in the ${}^{22}$Ne($p,\gamma$)${}^{23}$Na reaction
• On Potassium and Other Abundance Anomalies of Red Giants in NGC 2419
• Variations in the Na-O anticorrelation in globular clusters: Evidence for a deep mixing episode in red giant branch stars
• A high-resolution study of levels in the astrophysically important nucleus ${}^{26}$Mg and resulting updated level assignments
• First inverse kinematics study of the ${}^{22}$Ne$(p,\gamma {)}^{23}$Na reaction and its role in AGB star and classical nova nucleosynthesis
• First inverse kinematics measurement of key resonances in the ${}^{22}\text{Ne}(p,\gamma {)}^{23}\text{Na}$ reaction at stellar temperatures

Cited by in corpus (1)

• Solar fusion III: New data and theory for hydrogen-burning stars