New energy for the 133-keV resonance in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mmultiscripts><mml:mi>Na</mml:mi><mml:mprescripts/><mml:none/><mml:mn>23</mml:mn></mml:mmultiscripts><mml:mo>(</mml:mo><mml:mi mathvariant="normal">p</mml:mi><mml:mo>,</mml:mo><mml:mi>γ</mml:mi><mml:mo>)</mml:mo><mml:mmultiscripts><mml:mi>Mg</mml:mi><mml:mprescripts/><mml:none/><mml:mn>24</mml:mn></mml:mmultiscripts></mml:mrow></mml:math> reaction and its impact on nucleosynthesis in globular clusters
Caleb Marshall, K. Setoodehnia, Federico Portillo, J. H. Kelley, R. Longland
Abstract
Globular cluster stars exhibit star-to-star anticorrelations between oxygen and sodium in their atmospheres. An improved description of the sodium-destroying $^{23}\mathrm{Na}+\mathrm{p}$ reaction rates is essential to understanding these observations. We present an energy analysis of $^{24}\mathrm{Mg}$ states based on a new measurement of the $^{23}\mathrm{Na}(^{3}\mathrm{He},\mathrm{d})^{24}\mathrm{Mg}$ reaction. A key resonance in $^{23}\mathrm{Na}(\mathrm{p},\ensuremath{\gamma})^{24}\mathrm{Mg}$ is found to be at ${E}_{r}^{\text{c.m.}}=133(3)$ keV, 5 keV lower than previously adopted. This finding has a dramatic effect on the $^{23}\mathrm{Na}(\mathrm{p},\ensuremath{\gamma})^{24}\mathrm{Mg}$ reaction rate, increasing it by a factor of 2 for the recommended rate. The nucleosynthesis impact of this change is investigated.