Scientists at Stony Brook University have developed a novel approach to using high-energy particle collisions at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) to explore atomic nuclei shapes. This method, detailed in a recent Nature publication, offers a new perspective on nuclear structure that complements existing lower energy techniques.
Professor Jiangyong Jia, from the Department of Chemistry and adjunct professor in the Department of Physics and Astronomy, explained, “In this new measurement, we not only quantify the overall shape of the nucleus — whether it’s elongated like a football or squashed down like a tangerine — but also the subtle triaxiality.” Jia is one of the principal authors of the STAR Collaboration publication.
Understanding nuclear shapes is crucial for various physics inquiries, such as predicting atomic fission likelihoods, formation processes of heavy elements during neutron star collisions, and potential exotic particle decay discoveries. Enhanced knowledge of these shapes will provide insights into conditions resembling those in the early universe created during RHIC's energetic particle collisions.
The research method can be applied to additional data from RHIC and nuclear collision data from Europe's Large Hadron Collider (LHC). It also holds significance for future investigations at BNL's planned Electron-Ion Collider. RHIC operates as a U.S. Department of Energy Office of Science user facility dedicated to nuclear physics research.
Jia emphasized the importance of demonstrating how nuclear physics knowledge gained at RHIC can extend to other fields: “Now that we’ve demonstrated a robust way to image nuclear structure, there will be many applications.”
STAR scientists employed analysis of particle flow and momentum post-collision and compared them with hydrodynamic expansion models for different quark-gluon plasma shapes. They validated their method by contrasting central gold nuclei collisions—believed nearly spherical—with uranium nuclei collisions exhibiting an elongated shape.
For further details, visit the BNL website.