" NUclear CLustering Effects in Astrophysical Reactions: Nucleosynthesis in First Stars and Other Puzzles"

My project addresses three open questions in nuclear astrophysics: the cosmological lithium problem, the origin of carbon, nitrogen, and oxygen (CNO) in first-generation stars, and the so-called electron screening puzzle. All have eluded possible explanations for over three decades.

Despite appearing to be unrelated, these questions may all be reconciled by the quantum effect of nuclear clustering. This is a well-known phenomenon in nuclear physics, but its influence on low-energy nuclear reactions of astrophysical interest has remained largely unexplored until recently. The core idea of this project revolves around tantalising new evidence that nuclear clusters may enhance the fusion probability between certain light nuclei at very low energies and help answer the aforementioned questions.

Specifically, new fusion processes involving highly clustered light nuclei have recently been suggested to efficiently convert primordial hydrogen and helium into the CNO nuclei needed to gravitationally support first-generation stars, formed a few hundred million years after the Big Bang. Intriguingly, these same reactions could also substantially alter the abundance of lithium in these stars, thus potentially solving the cosmological lithium problem, i.e. a factor-of-three discrepancy between the predicted abundance of primordial lithium and that observed in the oldest stars today.

If low-energy nuclear reactions are indeed enhanced by clustering effects, the exceedingly high electron screening potential measured in laboratory studies of some astrophysical reactions could also be finally explained, with potentially enormous impact on fusion-driven energy generation.

By adopting a high-risk/high gain approach of experimental, theoretical, and computational effort, my team and I will break new ground in elucidating the role and strength of nuclear clustering in astrophysical reactions, with far-reaching consequences in nuclear physics, cosmology, and astrophysics.