New results from the ALICE Collaboration suggest quark-gluon plasma may form in proton collisions, not just heavy-ion experiments. A new analysis from the ALICE Collaboration is reshaping how physicists understand the conditions required to produce quark-gluon plasma (QGP), a state of matter thought to have existed moments after the Big Bang. The findings, published in Nature Communications, indicate that even relatively small particle collisions can exhibit characteristics long associated only with large-scale heavy-ion experiments. For decades, QGP has been studied by smashing heavy ions, such as lead nuclei, at extremely high energies. These collisions recreate the intense heat and density needed to free quarks and gluons from their usual confinement inside protons and neutrons. Smaller systems, like proton–proton collisions, were generally considered incapable of reaching those conditions. That assumption is now under increasing pressure. Evidence emerges from proton collisions The ALICE Collaboration analysed data from proton–proton and proton–lead collisions at the Large Hadron Collider (LHC), focusing on how particles emerge from these events. A key observable is ‘anisotropic flow,’ a phenomenon where particles are emitted …