2024/09/11 by Xing-Jian Lv, Xiaojun Bi, Lv, Xing-Jian +7
Physics and Astronomy · #Atomic and Subatomic Physics Research #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #High Energy Physics - Phenomenology (hep-ph) #Nuclear Physics and Applications #Radioactive Decay and Measurement Techniques
paper · pdf · doi:10.48550/arxiv.2409.07139
openalex publication_date 2024/09/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The recent AMS-02 measurements of cosmic-ray (CR) deuteron fluxes suggest the presence of primary deuterons in quantities far exceeding predictions from Big Bang nucleosynthesis. This poses a significant challenge to modern astrophysics, as no known processes can account for such large amounts of deuterons without violating existing constraints~\citeEpstein:1976hq. In contrast, it is recently proposed that the AMS-02 measurements can be explained by a purely secondary origin when contributions from heavier nuclei are considered. In this study, we recalculate the secondary deuteron flux using production cross sections updated with the latest collider data. We find that some of the deuteron production cross sections are overestimated in the widely-used calculation tools for CR propagation, and a primary deuteron component is still necessary. We then propose a novel process for generating primary deuterons at CR sources through a fusion mechanism, which is naturally unique to deuterons. This model could explain the observed deuteron excess while maintaining consistency with other CR measurements.