{"paper":{"title":"Two-photon production of dilepton pairs in peripheral heavy ion collisions","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ph"],"primary_cat":"nucl-th","authors_text":"Spencer R. Klein","submitted_at":"2018-01-12T21:25:16Z","abstract_excerpt":"The STAR collaboration has observed an excess production of $e^+e^-$ pairs in relativistic heavy ion collisions, over the expectations from hadronic production models. The excess pairs have transverse momenta $p_T < 150\\ {\\rm MeV}/c$ and are most prominent in peripheral gold-gold and uranium-uranium collisions. The pairs exhibit a peak at the $J/\\psi$ mass, but include a wide continuum, with pair invariant masses from 400 MeV/c$^2$ up to 2.6 GeV/c$^2$. The ALICE Collaboration observes a similar excess in peripheral lead-lead collisions, but only at the $J/\\psi$ mass, without a corresponding co"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1801.04320","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}