Physicists at the Large Hadron Collider have observed signs of quark-gluon plasma in collisions between oxygen and neon nuclei. This primordial state of matter existed during the first microseconds following the Big Bang. For years, scientists held the view that this plasma only appeared during collisions involving heavy lead ions. These new findings suggest that smaller nuclei are capable of producing the same extreme conditions.
The experiment utilized all four major collider detectors, including ALICE, ATLAS, CMS, and LHCb. Each experiment tracked how particles lost energy while passing through the dense, hot medium. By measuring the suppression of specific particles and the directional flow of matter, the teams confirmed that the plasma forms even when using lighter ions. The conditions inside these collisions reach temperatures over 100,000 times higher than the center of the Sun.
Energy loss acts as a primary indicator of this state. When fast-moving quarks travel through the plasma, they drain energy, creating an imbalance in particle jets. The data from neon-neon collisions shows this effect more clearly than oxygen-oxygen collisions, as the larger system generates a higher volume of plasma. This matches theoretical expectations for how matter behaves under such pressure.
Researchers continue to refine these measurements as the facility prepares for a transition to the High-Luminosity LHC. This transition will allow for more detailed analysis of the early Universe. The ability to create and measure this plasma provides a window into the fundamental forces that shaped the cosmos nearly 14 billion years ago.