Scientists have developed an innovative technique for studying nuclear structure using high-energy particle collisions at the Relativistic Heavy Ion Collider (RHIC), a U.S. Department of Energy (DOE) Office of Science user facility for nuclear physics research located at DOE’s Brookhaven National Laboratory. This groundbreaking method offers unprecedented insights into atomic nuclei’s shapes by analyzing the debris from nuclear smashups, complementing traditional low-energy experimental approaches.
The research, published in Nature, reveals a sophisticated approach to nuclear imaging that captures intricate details about nuclear geometry. By tracking particle emissions from central collisions between gold and uranium nuclei, scientists can effectively “reverse engineer” nuclear structures. Unlike previous long-exposure techniques that provided averaged measurements, this method generates multiple freeze-frame snapshots of nuclear configurations.
The team compared collisions between nearly spherical gold nuclei and elongated uranium nuclei, observing variations in particle flow patterns. Surprisingly, they discovered that uranium nuclei are more complex than previously understood, showing variations across all three principal axes rather than just one.
Computationally intensive, the research required over 20 million CPU hours to generate more than ten million collision events. The computational modeling and experimental data comparison allowed scientists to quantitatively describe uranium nucleus shape with unprecedented precision.
This breakthrough has far-reaching implications across multiple physics domains. It can help understand nuclear fission probabilities, investigate heavy element formation in neutron star collisions, and potentially illuminate exotic particle decay mechanisms. The method is applicable to future research at facilities like the Electron-Ion Collider and can be used to study isobar nuclei with potential applications in understanding rare decay processes.
Fundamentally, this research addresses a profound scientific quest: comprehending the nuclear building blocks that compose 99.9% of visible matter. By bridging high-energy and low-energy nuclear physics research communities, the study exemplifies collaborative scientific discovery that expands our understanding of fundamental matter’s structure.
Reference: “Imaging shapes of atomic nuclei in high-energy nuclear collisions” by STAR Collaboration, 6 November 2024, Nature. DOI: 10.1038/s41586-024-08097-2
This work was supported by the DOE Office of Science, the U.S. National Science Foundation (NSF), and a range of international agencies and organizations listed in the scientific paper.
