Cosmic Cauldrons: Probing Stellar Nucleosynthesis using Stable and Radioactive Beams

Ragandeep Singh Sidhu (University of Surrey, UK)

The elements that make up our world, including those in our own bodies, are forged in stars, either during their long quiescent burning phases or in the cataclysmic explosions that mark their deaths. Understanding these stellar processes requires precise measurements of fundamental nuclear properties, such as nuclear masses, stellar half-lives, and reaction rates at extremely low sub-Coulomb energies.
In this talk, I will present results from experiments using both stable and radioactive ion beams to address key questions in nuclear astrophysics. I will begin with recent results from the Experimental Storage Ring (ESR) at GSI/FAIR, including the first measurement of the half-life of bound-state beta decay in fully stripped ²⁰⁵Tl⁸¹⁺ [1], providing important constraints on the ²⁰⁵Pb-²⁰⁵Tl pair as a cosmic chronometer [2]. I will then turn to direct reaction studies with stable beams, performed both underground and at surface laboratories, where low-energy resonances in the ²¹Ne(p,γ)²²Na [3] and ⁴⁰Ca(p,γ)⁴¹Sc [4] reactions have been measured with high precision. Finally, I will discuss how future direct low-energy reaction measurements at GANIL could open new avenues in the field of nuclear astrophysics.

[1] R. S. Sidhu et al., PRL 133, 232701 (2024)
[2] G. Leckenby, et al., Nature 635, 321 (2024).
[3] R. S. Sidhu et al., PRC 112, L052801 (2025).
[4] R. S. Sidhu et al., PRC 111, 025804 (2025).