{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2009:EAVAD6RXD7YMT5H7NMC2BJZP23","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":"8466a7ac96744f0f9201c3590c07d868565d2ca8bd5b0c48d3e44ba280f9b772","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"hep-ph","submitted_at":"2009-10-01T16:07:01Z","title_canon_sha256":"094b51a693a190f2e8ce5cfedf0bc38b50199948b23084f772cad52101456b45"},"schema_version":"1.0","source":{"id":"0910.0209","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0910.0209","created_at":"2026-05-18T02:34:20Z"},{"alias_kind":"arxiv_version","alias_value":"0910.0209v1","created_at":"2026-05-18T02:34:20Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0910.0209","created_at":"2026-05-18T02:34:20Z"},{"alias_kind":"pith_short_12","alias_value":"EAVAD6RXD7YM","created_at":"2026-05-18T12:25:59Z"},{"alias_kind":"pith_short_16","alias_value":"EAVAD6RXD7YMT5H7","created_at":"2026-05-18T12:25:59Z"},{"alias_kind":"pith_short_8","alias_value":"EAVAD6RX","created_at":"2026-05-18T12:25:59Z"}],"graph_snapshots":[{"event_id":"sha256:b521ba02f546ecb0372157288554a01f6e1093eaa059fe81db98000f73be6d42","target":"graph","created_at":"2026-05-18T02:34:20Z","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":"The pion and nucleon mass differences generate a very pronounced cusp in the photoproduction reaction of a single neutral pion on the proton. A nonrelativistic effective field theory to describe this reaction is constructed. The approach is rigorous in the sense that it is an effective field theory with a consistent power counting scheme. Expressions for the S- and P-wave multipole amplitudes at one loop are given. The relation of the phase of the electric multipole E_0+ to the phase of the S-wave of pi^0 p --> pi^0 p scattering is discussed.","authors_text":"Andreas Fuhrer","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"hep-ph","submitted_at":"2009-10-01T16:07:01Z","title":"Photoproduction of neutral pions"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0910.0209","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":"sha256:19be0228d6b78028779e7942ce7f4bfab571433780ffc06fb3ba912adfb5227d","target":"record","created_at":"2026-05-18T02:34:20Z","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":"8466a7ac96744f0f9201c3590c07d868565d2ca8bd5b0c48d3e44ba280f9b772","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"hep-ph","submitted_at":"2009-10-01T16:07:01Z","title_canon_sha256":"094b51a693a190f2e8ce5cfedf0bc38b50199948b23084f772cad52101456b45"},"schema_version":"1.0","source":{"id":"0910.0209","kind":"arxiv","version":1}},"canonical_sha256":"202a01fa371ff0c9f4ff6b05a0a72fd6db28026a876af4d5fa995204ae95e100","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"202a01fa371ff0c9f4ff6b05a0a72fd6db28026a876af4d5fa995204ae95e100","first_computed_at":"2026-05-18T02:34:20.512624Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:34:20.512624Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"FB7FzPVw0nxnaafV2DcEuHmsQojHkSUsOF6O6VtiS3xCb/kQNpVrPuGIHd5OL6RzbUIhRaDCkq6bh5I6K2DRDA==","signature_status":"signed_v1","signed_at":"2026-05-18T02:34:20.513104Z","signed_message":"canonical_sha256_bytes"},"source_id":"0910.0209","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:19be0228d6b78028779e7942ce7f4bfab571433780ffc06fb3ba912adfb5227d","sha256:b521ba02f546ecb0372157288554a01f6e1093eaa059fe81db98000f73be6d42"],"state_sha256":"53af72d959a139dc68e4bba088e74bc322a521df667cc1b459a1333301b32703"}