Single neutron transfer on 23Ne and its relevance forthepathway ofnucleosynthesis in astrophysical X-ray bursts

TL;DR

This study measures resonance strengths in the 23Al(p, γ)24Si reaction using a radioactive 23Ne beam, reducing uncertainties in nucleosynthesis pathways relevant to X-ray bursts and showing the dominance of a specific proton capture process.

Contribution

First measurement of the (d, p) reaction on 23Ne to explore levels in 24Ne, providing key data to refine astrophysical reaction rates beyond 22Mg in X-ray burst scenarios.

Findings

Reduced uncertainty in the 23Al(p, γ) reaction rate by a factor of 4.

Identified the dominant nucleosynthesis pathway in X-ray bursts.

Showed the pathway's impact on energy production and hydrogen preservation.

Abstract

We present new experimental measurements of resonance strengths in the astrophysical 23Al(p, {\gamma})24Si reaction, constraining the pathway of nucleosynthesis beyond 22Mg in X-ray burster scenarios. Specifically, we have performed the first measurement of the (d, p) reaction using a radioactive beam of 23Ne to explore levels in 24Ne, the mirror analog of 24Si. Four strong single-particle states were observed and corresponding neutron spectroscopic factors were extracted with a precision of {\sim}20{\%}. Using these spectroscopic factors, together with mirror state identifications, we have reduced uncertainties in the strength of the key {\ell} = 0 resonance at Er= 157 keV, in the astrophysical 23Al(p, {\gamma}) reaction, by a factor of 4. Our results show that the 22Mg(p, {\gamma})23Al(p, {\gamma}) pathway dominates over the competing 22Mg({\alpha}, p) reaction in all but the most energetic X-ray burster events (T>0.85GK), significantly affecting energy production and the preservation of hydrogen fuel.