Stony Brook University researchers have made a significant contribution to developing a new method to reveal details on the shapes of atomic nuclei at the Relativistic Heavy Ion Collider (RHIC) in the Brookhaven National Laboratory.
The method, which was recently published in Nature, involves colliding ions such as gold and uranium together after stripping them of their electrons, leaving them with just the protons and electrons of their nuclei. This allows physicists to see features of the shapes and sizes of the nuclei.
Jiangyong Jia is one of the authors of the Solenoidal Tracker at RHIC (STAR) Collaboration publication and an adjunct professor in the Department of Physics and Astronomy. He began working with a large team of around 600 physicists in 2020 to gather data and perform complex statistical analyses for the STAR experiment.
While Jia saw this experiment as a challenge, he also believed it was very doable. Given that the experiment presented new ideas, the researchers first had to demonstrate that they would actually work.
“Nature doesn’t tell you this is the correct idea, you have to come up with a hypothesis, do an analysis and check whether they’re correct and do this many times,” Jia said.
The researchers started by conducting simulations of high-energy collisions and modeling the dynamics of their expansion, writing more than 10 papers to show that their method works, while disclosing any possible limitations it may have.
It took the team several years to understand how to perform the procedure with measurements that could construct the shape of a nucleus.
After they were sure their ideas were feasible, the group began writing their paper in January 2024 and sent it to Nature; it was recently published on Wednesday, Nov. 6.
“When you do science, especially when you do something new or exciting, it’s a long journey, because you need to convince yourself and convince your colleagues that you’re doing the right thing,” Jia said. “Then you need to convince the broader scientific community by submitting it to journals and getting them to agree.”
Jia and the rest of the physicists found the process of developing a new groundbreaking method to be very exciting.
“Whenever you do something new, you have this gut feeling that this new approach is right, but you have to prove it’s right,” Jia said. “That’s the most exciting part, you know; you have some good ideas and experience, but you have to perform tests and show that this method works.”
Somadutta Bhatta, a member of the STAR research team and a graduate student studying chemistry, was particularly delighted about the experiment due to the different perspectives that each researcher could contribute.
“What happened over the years is that we made our own efforts with Professor Jia and other students, and me, and we took our understanding of how we can make the measurements and how it would look like,” Bhatta said. “At the same time, we were in touch with other low-energy physicists who had their own understanding, so it was like finding out something entirely new, and finding out different perspectives of what we are made up of.”
While the team’s method is new, it is meant to complement the traditional method of measuring ion spectra by researching the electronic structures of the nuclei.
Even though the new method is more direct by showing images of the nuclei instead of relying on theoretical predictions, the older method remains more precise since it has been perfected over time.
However, the University’s physicists believe that the new method will provide an opportunity to learn novel insights and look at nuclear imaging problems from a different perspective. By combining the two methods, more can be learned about the shapes of nuclei, allowing the findings to be used outside of the lab and in real-world situations.
“Discovering the shape of nuclei will help us gain a deeper understanding of how nucleons form the nucleus. This knowledge is important for understanding fundamental physics,” Shengli Huang, a Stony Brook University researcher who worked closely with Jia on the experiment, said. “It can also be useful for applications such as synthesizing nuclei for new materials and in medical physics for cancer treatment.”
Jia hopes that the new method will eventually be perfected as time goes on, and that it can be used to combine other elements besides gold and uranium.
“The next step is to analyze those new species, the ones where the spectra is very complex,” Jia said. “We now have to use the method as a discovery tool.”
