Scientists Crack the Code of Unstable Atomic Nuclei Using Revolutionary Math

A team of nuclear physicists has developed a groundbreaking method to study broad resonances in atomic nuclei. The researchers—Rongzhe Hu, Nicolas Michel, Zhicheng Xu, Jianguo Li, and Furong Xu—extended the eigenvector continuation technique into complex-energy space. Their approach overcomes long-standing computational challenges in modelling unstable nuclei like hydrogen, helium, and four-neutron systems.

Broad resonances in nuclear physics have traditionally posed difficulties for theorists. These unstable states cause computational instability, making it hard to study open nuclei where particles easily break free. The team's solution involves using a small set of known stable or narrow resonance states as a starting point. By extrapolating from these, their method accurately predicts the behaviour of broad resonances without the need for exhaustive calculations.

The physicists tested their technique on hydrogen, helium, and four-neutron systems. Their results matched experimental observations, confirming the method's reliability. The work relies on the Gamow Shell Model, which solves the Schrödinger equation for nuclei while accounting for interactions between all protons and neutrons. This allows researchers to explore exotic structures, such as halo nuclei, which exhibit unusual decay patterns.

The study also sheds light on astrophysical processes where these nuclei form. Understanding their properties helps explain reactions in stars and other cosmic environments. Despite the progress, no new rare isotope facilities have opened in the past five years specifically to study such exotic nuclei. Existing upgrades, like those at PSI's muon facility or the planned IFMIF-DONES project, focus on broader nuclear research rather than helium-6 or helium-8.

The new method provides a powerful tool for nuclear structure research. It enables precise modelling of broad resonances in light nuclei, including hydrogen, helium, and four-neutron systems. This advancement supports further investigations into halo nuclei and their roles in astrophysical phenomena.