CERN Finds 4.9-Sigma Jet Quenching in Oxygen Collisions, Smallest Nuclear System Yet
Updated
Updated · spacedaily.com · Aug 31
CERN Finds 4.9-Sigma Jet Quenching in Oxygen Collisions, Smallest Nuclear System Yet
3 articles · Updated · spacedaily.com · Aug 31
Summary
ALICE found direct parton energy loss in oxygen-oxygen collisions, making them the smallest nuclear system yet with a decisive jet-quenching signal tied to quark-gluon plasma.
At 5.36 TeV per nucleon pair, the analysis saw neutral-pion suppression versus proton-proton data, then used proton-oxygen collisions as a control to rule out cold-nuclear-matter effects.
That double-ratio test stayed suppressed at 4.9 standard deviations relative to models without energy loss, strengthening the case that a hot medium drained jet energy in the 2025 oxygen run.
The result narrows a key boundary rather than proving oxygen is the smallest possible plasma source, since proton-based collisions have shown flow-like behavior but lacked direct jet-quenching evidence.
Across 2026 LHC studies, ATLAS, CMS and LHCb reported complementary suppression and flow patterns, helping map how quark-gluon-plasma signatures emerge as collision systems grow from protons toward lead.