{"paper":{"title":"Observation of an excess at 30 GeV in the opposite sign di-muon spectra of ${\\rm Z}^{0} \\to b\\overline{ b} + {\\rm X}$ events recorded by the ALEPH experiment at LEP","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"Arno Heister","submitted_at":"2016-10-20T18:50:56Z","abstract_excerpt":"The re-analysis of the archived data recorded at the ${\\rm Z}^{0}$ resonance by the ALEPH experiment at LEP during the years 1992-1995 shows an excess in the opposite sign di-muon mass spectra at 30.40 $\\pm$ 0.46 GeV in events containing b quarks. The excess has a natural width of 1.78 $\\pm$ 1.14 GeV.\n  The di-muon excess has a local significance around $5\\,\\sigma$ ($Z_{\\rm asym}$), depending on the background model used. The significances for background models based on a kernel density approximation stay close to $3\\,\\sigma$ ($Z_{\\rm freq,\\,lee}$), when including a look elsewhere effect. Anot"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1610.06536","kind":"arxiv","version":9},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/1610.06536/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}