{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:1999:LU6DWU7YNTELIX4WBMTAJX4FWN","short_pith_number":"pith:LU6DWU7Y","canonical_record":{"source":{"id":"nucl-th/9908068","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"nucl-th","submitted_at":"1999-08-20T21:04:13Z","cross_cats_sorted":[],"title_canon_sha256":"7dda2a934b6392adb090fd5c5619763e605b717235eb2397c639571a2529344e","abstract_canon_sha256":"843110d649a0b2f00a99d89cb20f5a122f985a2de5e2fe0e482b9d3b61ccdee2"},"schema_version":"1.0"},"canonical_sha256":"5d3c3b53f86cc8b45f960b2604df85b36cc0f7ed326dc235616f2d903d9bd908","source":{"kind":"arxiv","id":"nucl-th/9908068","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"nucl-th/9908068","created_at":"2026-05-18T01:05:17Z"},{"alias_kind":"arxiv_version","alias_value":"nucl-th/9908068v1","created_at":"2026-05-18T01:05:17Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.nucl-th/9908068","created_at":"2026-05-18T01:05:17Z"},{"alias_kind":"pith_short_12","alias_value":"LU6DWU7YNTEL","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_16","alias_value":"LU6DWU7YNTELIX4W","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_8","alias_value":"LU6DWU7Y","created_at":"2026-05-18T12:25:49Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:1999:LU6DWU7YNTELIX4WBMTAJX4FWN","target":"record","payload":{"canonical_record":{"source":{"id":"nucl-th/9908068","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"nucl-th","submitted_at":"1999-08-20T21:04:13Z","cross_cats_sorted":[],"title_canon_sha256":"7dda2a934b6392adb090fd5c5619763e605b717235eb2397c639571a2529344e","abstract_canon_sha256":"843110d649a0b2f00a99d89cb20f5a122f985a2de5e2fe0e482b9d3b61ccdee2"},"schema_version":"1.0"},"canonical_sha256":"5d3c3b53f86cc8b45f960b2604df85b36cc0f7ed326dc235616f2d903d9bd908","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:05:17.674907Z","signature_b64":"gN4a55bqkNnYb0CaFm9ZB8t+nxTuVgEGSF7GMkNHzCauVnpXUbgnbTZthgexfsNK+f4cuUC+0lwzeNoWkYADBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"5d3c3b53f86cc8b45f960b2604df85b36cc0f7ed326dc235616f2d903d9bd908","last_reissued_at":"2026-05-18T01:05:17.674032Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:05:17.674032Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"nucl-th/9908068","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:05:17Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"luOVkg6rtXJoszOH7j30IAs5OxOeKoq6OpsmdQ7WruLe6rvopjD3piNl+vRkeL6yARzBevaFfI4YvkV7bTJxCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T14:29:43.483368Z"},"content_sha256":"ca6be0443d8eba641d5f7faec5c3c6098affa0828e0e833b923a0ab23b77e172","schema_version":"1.0","event_id":"sha256:ca6be0443d8eba641d5f7faec5c3c6098affa0828e0e833b923a0ab23b77e172"},{"event_type":"graph_snapshot","subject_pith_number":"pith:1999:LU6DWU7YNTELIX4WBMTAJX4FWN","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Constraints on vector meson photoproduction spin observables","license":"","headline":"","cross_cats":[],"primary_cat":"nucl-th","authors_text":"Frank Tabakin, W.M. Kloet","submitted_at":"1999-08-20T21:04:13Z","abstract_excerpt":"Extraction of spin observables from vector meson photoproduction on a nucleon target is described. Starting from density matrix elements in the vector meson's rest frame, we transform to spin observables in the photon-nucleon c.m. frame.\n Several constraints on the transformed density matrix and on the spin observables follow from requiring that the angular distribution and the density matrix be positive definite. A set of constraints that are required in order to extract meaningful spin observables from forthcoming data are enunciated."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"nucl-th/9908068","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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:05:17Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"XRhb5eVbEj2Ij7G5xw3AxuOQXiB0mhDGgvhoPgp0fBpfTLtUHfOrO0mOESVTfh9dtkkgRjVrs9gNEtyAji4SCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T14:29:43.483903Z"},"content_sha256":"4b748ba28c9f8ed15f5145b7c718d3083331c85e3eb2ed6fd1bbf4d253aba052","schema_version":"1.0","event_id":"sha256:4b748ba28c9f8ed15f5145b7c718d3083331c85e3eb2ed6fd1bbf4d253aba052"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/LU6DWU7YNTELIX4WBMTAJX4FWN/bundle.json","state_url":"https://pith.science/pith/LU6DWU7YNTELIX4WBMTAJX4FWN/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/LU6DWU7YNTELIX4WBMTAJX4FWN/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-05-31T14:29:43Z","links":{"resolver":"https://pith.science/pith/LU6DWU7YNTELIX4WBMTAJX4FWN","bundle":"https://pith.science/pith/LU6DWU7YNTELIX4WBMTAJX4FWN/bundle.json","state":"https://pith.science/pith/LU6DWU7YNTELIX4WBMTAJX4FWN/state.json","well_known_bundle":"https://pith.science/.well-known/pith/LU6DWU7YNTELIX4WBMTAJX4FWN/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:1999:LU6DWU7YNTELIX4WBMTAJX4FWN","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"843110d649a0b2f00a99d89cb20f5a122f985a2de5e2fe0e482b9d3b61ccdee2","cross_cats_sorted":[],"license":"","primary_cat":"nucl-th","submitted_at":"1999-08-20T21:04:13Z","title_canon_sha256":"7dda2a934b6392adb090fd5c5619763e605b717235eb2397c639571a2529344e"},"schema_version":"1.0","source":{"id":"nucl-th/9908068","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"nucl-th/9908068","created_at":"2026-05-18T01:05:17Z"},{"alias_kind":"arxiv_version","alias_value":"nucl-th/9908068v1","created_at":"2026-05-18T01:05:17Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.nucl-th/9908068","created_at":"2026-05-18T01:05:17Z"},{"alias_kind":"pith_short_12","alias_value":"LU6DWU7YNTEL","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_16","alias_value":"LU6DWU7YNTELIX4W","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_8","alias_value":"LU6DWU7Y","created_at":"2026-05-18T12:25:49Z"}],"graph_snapshots":[{"event_id":"sha256:4b748ba28c9f8ed15f5145b7c718d3083331c85e3eb2ed6fd1bbf4d253aba052","target":"graph","created_at":"2026-05-18T01:05:17Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"Extraction of spin observables from vector meson photoproduction on a nucleon target is described. Starting from density matrix elements in the vector meson's rest frame, we transform to spin observables in the photon-nucleon c.m. frame.\n Several constraints on the transformed density matrix and on the spin observables follow from requiring that the angular distribution and the density matrix be positive definite. A set of constraints that are required in order to extract meaningful spin observables from forthcoming data are enunciated.","authors_text":"Frank Tabakin, W.M. Kloet","cross_cats":[],"headline":"","license":"","primary_cat":"nucl-th","submitted_at":"1999-08-20T21:04:13Z","title":"Constraints on vector meson photoproduction spin observables"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"nucl-th/9908068","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:ca6be0443d8eba641d5f7faec5c3c6098affa0828e0e833b923a0ab23b77e172","target":"record","created_at":"2026-05-18T01:05:17Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"843110d649a0b2f00a99d89cb20f5a122f985a2de5e2fe0e482b9d3b61ccdee2","cross_cats_sorted":[],"license":"","primary_cat":"nucl-th","submitted_at":"1999-08-20T21:04:13Z","title_canon_sha256":"7dda2a934b6392adb090fd5c5619763e605b717235eb2397c639571a2529344e"},"schema_version":"1.0","source":{"id":"nucl-th/9908068","kind":"arxiv","version":1}},"canonical_sha256":"5d3c3b53f86cc8b45f960b2604df85b36cc0f7ed326dc235616f2d903d9bd908","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"5d3c3b53f86cc8b45f960b2604df85b36cc0f7ed326dc235616f2d903d9bd908","first_computed_at":"2026-05-18T01:05:17.674032Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:05:17.674032Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"gN4a55bqkNnYb0CaFm9ZB8t+nxTuVgEGSF7GMkNHzCauVnpXUbgnbTZthgexfsNK+f4cuUC+0lwzeNoWkYADBg==","signature_status":"signed_v1","signed_at":"2026-05-18T01:05:17.674907Z","signed_message":"canonical_sha256_bytes"},"source_id":"nucl-th/9908068","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ca6be0443d8eba641d5f7faec5c3c6098affa0828e0e833b923a0ab23b77e172","sha256:4b748ba28c9f8ed15f5145b7c718d3083331c85e3eb2ed6fd1bbf4d253aba052"],"state_sha256":"c6f1120a2a59fccb1544b59440b055449f60ae57e918a8a1df3e3077c6ce95ea"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ZjeWezxc7AOtDoDJP63fg5IBFRqU9FfL27ZsqKd9++EDrcpB7wLEe8e5LU5r+S/Bub/ME2STjH+AztLt4zdPAg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-31T14:29:43.486990Z","bundle_sha256":"b32b3b406ad95d56e31d39120375c5efc5422e5b4e220b34ac108ea864f63d1b"}}