Nuclear Structure and Reactions in Heavy and Superheavy Nuclei

The study of heavy and superheavy nuclei probes the limits of nuclear stability and the interplay between quantum shells, collective deformations and strong Coulomb forces. In these systems, long‐standing shell closures may shift or vanish under extreme proton and neutron numbers, giving rise to novel shapes and isomeric states. Theoretical approaches combine macroscopic–microscopic models, self-consistent mean-field and beyond-mean-field methods to predict ground-state deformations, pairing correlations and fission barriers. Reaction studies focus on fusion dynamics, competition between compound-nucleus formation and quasi-fission, and multi-nucleon transfer processes in deep-inelastic collisions. These investigations guide the synthesis of new elements, inform models of rapid neutron capture in astrophysics and underpin applications in radiochemistry and materials science. Experimental advances in recoil separators, high-resolution detectors and radioactive beams are extending our reach toward the predicted “island of stability” and refining our understanding of decay pathways in the heaviest nuclides.

Research from Nature Portfolio

Recent studies of collisions between medium-mass and heavy nuclei reveal a far richer landscape of mass and charge exchange prior to capture than previously appreciated. Investigations of calcium-lead interactions at near-barrier energies demonstrate that dozens of neutron-proton partitions can emerge in each encounter. Each partition carries its own likelihood of progressing to a compact superheavy compound system, indicating that the early transfer stage critically shapes overall fusion probability. This multi-channel transfer “explosion” challenges standard capture models and points to the need for dynamical frameworks that incorporate stochastic nucleon flow and shape evolution in the approach phase.

Nuclear Structure and Reactions in Heavy and Superheavy Nuclei publication trend

The graph below shows the total number of articles in nuclear structure and reactions in heavy and superheavy nuclei across all publications each year (not limited to Nature Index journals).

Technical terms

Shell closure: A configuration in which proton or neutron energy levels are filled to “magic” numbers, conferring extra stability to the nucleus.

Quasi-fission: A rapid reaction pathway in heavy-ion collisions where the system reseparates without forming an equilibrated compound nucleus.

Multi-nucleon transfer reaction: A process in which several protons and neutrons are exchanged between colliding nuclei, often producing new isotopes.

Compound nucleus: A transient, thermally equilibrated nucleus formed when two nuclei fully merge after overcoming the Coulomb repulsion.

Fission barrier: The potential energy maximum that a nucleus must surmount to split into two fragments.

Coulomb barrier: The electrostatic repulsive energy barrier between two positively charged nuclei that must be overcome for fusion to occur.

References

1. Calorimetric low temperature detectors for heavy ion physics and their application in nuclear and atomic physics. Progress in Particle and Nuclear Physics (2023).
2. Colliding heavy nuclei take multiple identities on the path to fusion. Nature Communications (2023).
3. The NUBASE2020 evaluation of nuclear physics properties. Chinese Physics C (2021).
4. Future of nuclear fission theory. Journal of Physics G Nuclear and Particle Physics (2020).