{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"70a6752f33683a8eab1e8e90155d0531e4f852e72981d7b2ccd9a7eff823cf5c","created":"2026-10-03T07:18:07Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"2002e0d331ba0bf16964476dc76ee39d35ca35cc8e1959e30cc497ce641b2de7","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"nuc.quark-gluon-plasma.chiral-magnetic-effect","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"In the strong magnetic field of a heavy-ion collision, regions with unequal numbers of left- and right-handed quarks should push positive and negative charges in opposite directions along the field, an effect called the chiral magnetic effect. Measured charge-separation signals can so far be explained by ordinary background effects.","posed_since":"2008","precise":"The effect predicts charge separation along the magnetic field, measured by the correlator $\\Delta \\gamma = \\gamma_{\\mathrm{OS}} - \\gamma_{\\mathrm{SS}}$. The STAR blind analysis of Ru+Ru versus Zr+Zr at $\\sqrt{s_{NN}} = 200\\,\\mathrm{GeV}$ found no signature meeting predefined criteria (arXiv 2109.00131), and a later analysis set an upper limit of 10 percent at 95 percent confidence on the effect's fraction of the measured correlator (Phys. Rev. Research 6, L032005, 2024). Answer: a nonzero fraction at 5 standard deviations, or an upper limit below the range predicted by anomalous-hydrodynamics models with realistic magnetic-field lifetimes.","problem_ref":null,"references":"","settled_by":"Charge-separation measurements relative to spectator and participant planes in Au+Au and isobar collisions with backgrounds fixed by event-shape selection, compared with anomalous-hydrodynamics predictions.","status_note":"The 2024 STAR upper limit of 10 percent left room for a small contribution; no established signal existed as of 2026.","title":"Does the chiral magnetic effect occur in heavy-ion collisions?","topic_ref":"ec5bb29d3c4ec6576273c8009fdd00011a21f5672430b3080013ab67a0a1a41c"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"922331e78831f73d9780b2d25eb58613abae446a1497d026de8b986caa8241cf","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"89bed9b9cba13e535e7ce2839d6302358abf72046fe69b1ee8967ba5254964f8","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"Zml1Qbr4KGLQ6a79lYw09RwRV6pjQc4AMRTKQ1WxYlzHeIwdWxlvWptrIypW3oo3g-GLDXmwr8Hw0pouU0SuCA"},"schema":"pubphys.envelope/1"},"record_hash":"922331e78831f73d9780b2d25eb58613abae446a1497d026de8b986caa8241cf","leaf_index":1802}