{"paper":{"title":"Search for anomalously heavy isotopes of helium in the Earth's atmosphere","license":"","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"J. P. Schiffer, L.-B. Wang, P. Mueller, R. J. Holt, T. P. O'Connor, Z.-T. Lu","submitted_at":"2003-02-21T15:57:00Z","abstract_excerpt":"Motivated by the theoretical hypotheses on the existence of heretofore unobserved stable elementary particles and exotic nuclear states, we searched for doubly-charged particles, as anomalously heavy isotopes of helium, in the Earth's atmoshpere using a sensitive laser spectroscopy technique. The concentration of noble-gas-like atoms in the atmosphere and the subsequent very large depletion of the light He-3,4 isotopes allow us to set stringent limits on th abundance: 10^-13 to 10^-17 per atom in the solar system, over the mass range of 20 to 10,000 amu."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"nucl-ex/0302025","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/nucl-ex/0302025/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"}