Scientists at the Niels Bohr Institute in the Netherlands have successfully recreated a miniature version of the conditions immediately following the Big Bang by colliding smaller atomic nuclei than previously thought possible. The experiment utilized oxygen-16 and neon-20 atoms, fired at nearly the speed of light, to generate a tiny blob of quark-gluon plasma, a state of matter believed to have existed in the universe's earliest moments.
This achievement marks a significant advancement, as physicists previously believed that creating this primordial soup required smashing heavier atoms like lead. "We have pushed the boundary for how small the atomic nuclei can be while still re-creating this primordial matter — what you could call a ‘little big bang,’" said You Zhou, a researcher who led the study. The team can now explore the fundamental conditions required for matter to transition into this extreme state.
The experiment involves colliding the oxygen and neon nuclei. This collision produces a fleeting droplet of quark-gluon plasma that expands and cools almost instantaneously. While too fast to observe directly, researchers study the resulting particles to infer the plasma's behavior. An unexpected finding emerged when comparing collisions of different atoms. When two oxygen atoms collided, the ejected particles sprayed out in a rounded pattern. However, collisions between two neon atoms resulted in particles shaped more like a bowling pin, a pattern that corresponds to the geometric shape of a neon nucleus.
This difference provided researchers with an indirect method to visualize atomic shapes that are otherwise impossible to observe directly. "Hopefully, this will help us better understand how the plasma behaved during the first moments of the universe — and how it later evolved into the forms of matter that everything around us is made of," Zhou explained. Emil Gorm Dahlbæk Nielsen, a postdoctoral researcher at the Niels Bohr Institute and coauthor, added that by studying particle movement after collisions, scientists can gain insights into atomic nuclei that are difficult to obtain through other means.
The findings, published in the journal Physical Review Letters, offer additional support for the standard Big Bang theory. This research emerges as some in the scientific community continue to explore alternative cosmological models, such as the