{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2019:AMZ7XCPY2X6ZS2YP6AVETARIBR","short_pith_number":"pith:AMZ7XCPY","schema_version":"1.0","canonical_sha256":"0333fb89f8d5fd996b0ff02a4982280c6f465d1246ddb635be6f2f17457ec8a1","source":{"kind":"arxiv","id":"1907.10573","version":1},"attestation_state":"computed","paper":{"title":"Positronium formation in graphene and graphite","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mes-hall","authors_text":"A. H. Weiss, A. J. Fairchild, A. R. Koymen, M. D. Chrysler, R. W. Gladen, V. A. Chirayath","submitted_at":"2019-07-24T17:24:44Z","abstract_excerpt":"Positronium (Ps) formation on the surface of clean polycrystalline copper (Cu), highly oriented pyrolytic graphite (HOPG) and multi layer graphene (MLG) grown on a polycrystalline copper substrate has been investigated as a function of incident positron kinetic energy (1.5eV to 1keV). Measurments on Cu indicate that as the kinetic energy of the incident positrons increases from 1.5eV to 900eV, the fraction of positrons that form Ps ($f_{Ps}$) decreases from ~0.5 to ~0.3. However, in HOPG and MLG, instead of a monotonic decrease of $f_{Ps}$ with positron kinetic energy, a sharp peak is observed"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1907.10573","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2019-07-24T17:24:44Z","cross_cats_sorted":[],"title_canon_sha256":"9e00824953e8ffe2dc2e007a4aaed78fef31370153fe39f4315d9113cce27e6a","abstract_canon_sha256":"4300b8a720a56ebd1f04f94de9ae98420c09b18dc52cb9f634899b5e77eb69a3"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T00:36:29.786411Z","signature_b64":"YPGh4krAK04Ra3226mzSlrSVC5Rl+qBGcO24kku+SW0f9eGsbLRJxeAB59DeHjp3AQXH/PtGxslDKEpW6s+2Ag==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"0333fb89f8d5fd996b0ff02a4982280c6f465d1246ddb635be6f2f17457ec8a1","last_reissued_at":"2026-07-05T00:36:29.786050Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T00:36:29.786050Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Positronium formation in graphene and graphite","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mes-hall","authors_text":"A. H. Weiss, A. J. Fairchild, A. R. Koymen, M. D. Chrysler, R. W. Gladen, V. A. Chirayath","submitted_at":"2019-07-24T17:24:44Z","abstract_excerpt":"Positronium (Ps) formation on the surface of clean polycrystalline copper (Cu), highly oriented pyrolytic graphite (HOPG) and multi layer graphene (MLG) grown on a polycrystalline copper substrate has been investigated as a function of incident positron kinetic energy (1.5eV to 1keV). Measurments on Cu indicate that as the kinetic energy of the incident positrons increases from 1.5eV to 900eV, the fraction of positrons that form Ps ($f_{Ps}$) decreases from ~0.5 to ~0.3. However, in HOPG and MLG, instead of a monotonic decrease of $f_{Ps}$ with positron kinetic energy, a sharp peak is observed"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.10573","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/1907.10573/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"},"aliases":[{"alias_kind":"arxiv","alias_value":"1907.10573","created_at":"2026-07-05T00:36:29.786111+00:00"},{"alias_kind":"arxiv_version","alias_value":"1907.10573v1","created_at":"2026-07-05T00:36:29.786111+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1907.10573","created_at":"2026-07-05T00:36:29.786111+00:00"},{"alias_kind":"pith_short_12","alias_value":"AMZ7XCPY2X6Z","created_at":"2026-07-05T00:36:29.786111+00:00"},{"alias_kind":"pith_short_16","alias_value":"AMZ7XCPY2X6ZS2YP","created_at":"2026-07-05T00:36:29.786111+00:00"},{"alias_kind":"pith_short_8","alias_value":"AMZ7XCPY","created_at":"2026-07-05T00:36:29.786111+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/AMZ7XCPY2X6ZS2YP6AVETARIBR","json":"https://pith.science/pith/AMZ7XCPY2X6ZS2YP6AVETARIBR.json","graph_json":"https://pith.science/api/pith-number/AMZ7XCPY2X6ZS2YP6AVETARIBR/graph.json","events_json":"https://pith.science/api/pith-number/AMZ7XCPY2X6ZS2YP6AVETARIBR/events.json","paper":"https://pith.science/paper/AMZ7XCPY"},"agent_actions":{"view_html":"https://pith.science/pith/AMZ7XCPY2X6ZS2YP6AVETARIBR","download_json":"https://pith.science/pith/AMZ7XCPY2X6ZS2YP6AVETARIBR.json","view_paper":"https://pith.science/paper/AMZ7XCPY","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1907.10573&json=true","fetch_graph":"https://pith.science/api/pith-number/AMZ7XCPY2X6ZS2YP6AVETARIBR/graph.json","fetch_events":"https://pith.science/api/pith-number/AMZ7XCPY2X6ZS2YP6AVETARIBR/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/AMZ7XCPY2X6ZS2YP6AVETARIBR/action/timestamp_anchor","attest_storage":"https://pith.science/pith/AMZ7XCPY2X6ZS2YP6AVETARIBR/action/storage_attestation","attest_author":"https://pith.science/pith/AMZ7XCPY2X6ZS2YP6AVETARIBR/action/author_attestation","sign_citation":"https://pith.science/pith/AMZ7XCPY2X6ZS2YP6AVETARIBR/action/citation_signature","submit_replication":"https://pith.science/pith/AMZ7XCPY2X6ZS2YP6AVETARIBR/action/replication_record"}},"created_at":"2026-07-05T00:36:29.786111+00:00","updated_at":"2026-07-05T00:36:29.786111+00:00"}