{"paper":{"title":"A stringent upper limit on the direct 3$\\alpha$ decay of the Hoyle State in $^{12}$C","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["nucl-th"],"primary_cat":"nucl-ex","authors_text":"D. Schweitzer, H. O. U. Fynbo, M. Freer, M. Gai, M. W. Ahmed, R. Smith, S. R. Stern","submitted_at":"2020-01-20T19:12:39Z","abstract_excerpt":"We investigate an implication of the most recent observation of a second $J^\\pi = 2^+$ state in $^{12}$C, which was measured using the $^{12}$C($\\gamma$,$\\alpha$)$^8$Be$_{\\textrm{(g.s.)}}$ reaction. In addition to the dissociation of $^{12}$C to an $\\alpha$-particle and $^8$Be in its ground state, a small fraction of events (2%) were identified as direct decays and decays to excited states in $^8$Be. This allowed a limit on the direct 3$\\alpha$ partial decay width to be determined as $\\Gamma_{3\\alpha} < 32(4)$ keV. Since this 2$^+$ state is predicted by all theoretical models to be a collectiv"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2001.07223","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2001.07223/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"}