Plate Nº 46 · recorded October 10, 2026
PhysicsReported finding
Physicists Create Mini 'Big Bang' Using Surprisingly Small Atoms
CERN physicists produced quark-gluon plasma—the state of matter from the Universe's first millionth of a second—using oxygen-16 and neon-20 nuclei, far smaller than the heavy nuclei once thought required.
By Elena Vasquez3 min read665 words
In brief
- Findings published August 23, 2026 in Physical Review Letters, Volume 137, Issue 8
- Collisions ran at a center-of-mass energy of 5.36 TeV per nucleon pair
- Oxygen-16 (8 protons, 8 neutrons) and neon-20 (10 protons, 10 neutrons) nuclei produced the plasma
- Aage Bohr received the 1975 Nobel Prize in Physics for work on nuclear structure at the Niels Bohr Institute
- Next planned experiments will use helium-4 nuclei to probe the lower size limit
Physicists at CERN have produced quark-gluon plasma—the matter that filled the Universe during its first millionth of a second after the Big Bang—by colliding oxygen-16 and neon-20 atomic nuclei at nearly the speed of light. The findings, dated August 23, 2026 and published in Physical Review Letters, overturn a long-held assumption that only very heavy nuclei could generate this primordial material.
The experiments ran at a center-of-mass energy of 5.36 TeV per nucleon pair as part of the ALICE collaboration, an international effort involving researchers from the Niels Bohr Institute at the University of Copenhagen and dozens of other institutions.
What did scientists actually make?
Quark-gluon plasma is an ultra-hot, dense state of matter in which the building blocks of protons and neutrons—quarks and gluons—move freely rather than being bound together. Temperatures in the early Universe were so extreme that protons and neutrons had not yet formed.
"We have pushed the boundary for how small the atomic nuclei can be while still recreating this primordial matter—what you could call a Little Big Bang," said Associate Professor You Zhou, who led the experiment. "We now know more about the fundamental conditions required for matter to transition into this extreme state."
Why is this surprising?
For decades, physicists believed that producing quark-gluon plasma required smashing the heaviest available nuclei together, such as lead-208. The new results show that nuclei with only 16 to 20 protons and neutrons can do the job. His team collided oxygen-16 with oxygen-16 and neon-20 with neon-20, recording the particles produced in the aftermath.
How can collisions reveal nuclear shape?
The plasma itself survives for only a tiny fraction of a second and cannot be observed directly. Researchers instead measure the particles that emerge and study their movement patterns. Those patterns preserve information about the geometric shape of the colliding nuclei.
Collisions between two spherical oxygen nuclei produce a relatively rounded pattern. Neon-20 collisions generate a distinctive bowling-pin-shaped pattern.
"It is a bit like shining light on an object and seeing its shadow," said Postdoctoral Researcher Emil Gorm Dahlbæk Nielsen of the Niels Bohr Institute. "You cannot see the object directly, but its shadow reveals its shape. In the same way, the movement of the particles reveals the geometric shape of the atomic nuclei."
What does this mean for nuclear physics?
Physicists have investigated the shapes and internal structures of atomic nuclei for more than 70 years. The question carries deep historical weight at the Niels Bohr Institute: Aage Bohr received the 1975 Nobel Prize in Physics for his work on nuclear structure.
Traditionally, researchers probed nuclei using low-energy experiments that tracked how nuclei rotate and vibrate. The new approach reverses that strategy. By colliding nuclei at the highest available energies, they reconstruct shapes from particle patterns left behind.
"A precise understanding of nuclear structure helps us understand the strong force," Zhou said. "But instead of carefully investigating nuclei at low energies, we smash them together at the highest energies we can create."
How small can the colliding nuclei get?
Scientists do not yet know the lower size limit for a collision system that still produces quark-gluon plasma. Zhou's team plans additional experiments with helium-4, which contains only two protons and two neutrons, to probe that boundary.
If refined, the technique could open a new window onto atomic nuclei whose internal structures remain poorly understood. The researchers describe the method as a potential paradigm shift.
"What is fascinating is that we can use the same experiment both to learn about the structure of atomic nuclei and to gain a better understanding of what happened during the birth of the Universe," Zhou concluded. "These two things turn out to be much more closely connected than one might initially think."
The full study appears in Physical Review Letters, Volume 137, Issue 8 (2026), DOI: 10.1103/gymp-vp87.
via news.ku.dk (Original)
More from Elena Vasquez
Nearby plates
- CERN Experiment Sees Gluons Act Collectively at Record-Small Scales
- Jet Diffusion Wakes Detected in Quark-Gluon Plasma, 20 Years On
- Big Bang Nucleosynthesis Makes a Comeback in Modern Cosmology
- JWST Spots Heavy Elements Escaping the Universe's First Galaxies
- CERN's Super Proton Synchrotron Marks 50 Years of Particle Physics Firsts