Probing SHN Structure and Stability — Synthesis and Decay Studies at S\(^3\)

The superheavy nuclei (SHN), residing at the edge of nuclear stability at the highest atomic charge \(Z\) and mass \(A\), are in the focus of scientific efforts worldwide due to the high discovery potential offered by their investigation. In this paper, we report on some of the major challenges and how we intend to approach them at GANIL, with advanced instrumentation and state-of-the-art experimental methods, as well as reaction theory approaches to the SHN production mechanism. Decay Spectroscopy After Separation (DSAS) is an efficient tool to study nuclear structure features of the heaviest nuclear species such as single particle trends towards the predicted next spherical shell closures beyond \(^{208}\)Pb, and deformation and exotic shapes, leading also to the formation of meta-stable states, like, <span class="it">e.g.</span> , \(K\)-isomers. The understanding of the reaction mechanism governing heavy collisions employed for the synthesis of the heaviest nuclei, despite decades of experimental and theoretical efforts, is still a challenging task. Being a fundamental topic by itself, mastering reaction theory and producing reliable cross-section predictions are essential for a successful experimental program. Detailed nuclear structure studies of the heaviest nuclei, as well as the synthesis of superheavy elements (SHE) are presently still hampered by the limited efficiencies of the existing experimental facilities. To overcome this restriction, substantial efforts are being made to upgrade and develop existing and new facilities worldwide, online since recently or planned for the future, including the linear accelerator facility SPIRAL2 at GANIL, equipped with the versatile separator–spectrometer set-up S\(^3\). Abstract Published by the Jagiellonian University 2026 authors