Oxygen collisions at the LHC show new indications of extreme state of matter

The Large Hadron Collider (LHC) has detected new indications that oxygen and neon collisions could produce the extreme state of matter believed to have existed just moments after the Big Bang. All four major LHC experiments, ALICE, ATLAS, CMS, and LHCb, reported findings suggesting the formation of quark, gluon plasma (QGP), a superhot, dense phase of matter that emerged in the early universe. These results come one year after the first-ever oxygen collisions at the LHC, marking a significant advancement in understanding the fundamental forces and conditions of the cosmos. Oxygen and neon collisions at the LHC represent a departure from previous methods used to generate QGP, which traditionally required collisions involving much heavier nuclei, such as lead. Until recently, scientists believed that only heavy-ion collisions could achieve the extreme pressures and temperatures needed to create QGP. However, recent studies challenge this assumption, showing that lighter nuclei like oxygen and neon might also produce this exotic state of matter. The discovery stems from extensive analyses conducted by the LHC collaborations, who examined data from oxygen, oxygen and neon, neon collisions over several months. Parton energy loss, a key indicator of QGP formation, is evident in the data collected by the ATLAS experiment. This phenomenon occurs when fast-moving quarks and gluons lose energy as they travel through the dense, hot medium of QGP. ATLAS observed an imbalance between pairs of particle jets produced in oxygen, oxygen and neon, neon collisions, indicating that energy was being lost. This effect became more pronounced in central collisions, where a larger volume of QGP is formed, leading to greater energy loss. Preliminary studies of charged particles recoiling against photons also showed similar dependencies, reinforcing the link between energy loss and QGP. Other experiments took alternative approaches to confirm the presence of QGP. The CMS collaboration noted a suppression of charged-particle production in oxygen, oxygen and neon, neon collisions compared to proton, proton collisions. This suppression suggests that parton energy loss is occurring, further supporting the idea that QGP is forming in these lighter ion collisions. Meanwhile, the LHCb experiment studied the suppression of particles made of charm and light quarks in oxygen, oxygen and neon, neon collisions. They found that the suppression increased with the mass of the colliding nuclei, aligning with expectations based on parton energy loss and the expansion of QGP volume. To rule out alternative explanations for the observed effects, the ALICE collaboration compared the production of neutral pions in oxygen, oxygen and proton, oxygen collisions. Their analysis confirmed that parton energy loss was responsible for the suppression, providing clear evidence of QGP formation in oxygen, oxygen collisions. This method helped eliminate other possible factors contributing to the observed phenomena, strengthening the case for QGP creation in these lighter ion interactions. The implications of these findings extend beyond confirming the existence of QGP. They suggest that the conditions necessary for QGP formation may be achievable with a broader range of collision types than previously thought. This opens new avenues for research, allowing scientists to explore the properties of QGP using lighter nuclei and potentially uncovering additional insights into the behavior of matter under extreme conditions. As the LHC continues to refine its analyses, future studies may reveal even more nuanced characteristics of QGP, offering deeper understanding of the universe’s earliest moments.