{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:KQP6M6T3JM3ECZV4MB3PGYHNGA","short_pith_number":"pith:KQP6M6T3","canonical_record":{"source":{"id":"1804.06661","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"nucl-ex","submitted_at":"2018-04-18T11:40:37Z","cross_cats_sorted":[],"title_canon_sha256":"40616f2407fc720aaaba20e1636bc68cb02b27044b65eda9263f739d29287d83","abstract_canon_sha256":"06dbd31e2ad7e24e150f110c299142c65b816ceedc16072d483759dd6288c502"},"schema_version":"1.0"},"canonical_sha256":"541fe67a7b4b364166bc6076f360ed3008f31c48f88f4558b2b766f7c7f8b306","source":{"kind":"arxiv","id":"1804.06661","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1804.06661","created_at":"2026-05-18T00:13:26Z"},{"alias_kind":"arxiv_version","alias_value":"1804.06661v1","created_at":"2026-05-18T00:13:26Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1804.06661","created_at":"2026-05-18T00:13:26Z"},{"alias_kind":"pith_short_12","alias_value":"KQP6M6T3JM3E","created_at":"2026-05-18T12:32:33Z"},{"alias_kind":"pith_short_16","alias_value":"KQP6M6T3JM3ECZV4","created_at":"2026-05-18T12:32:33Z"},{"alias_kind":"pith_short_8","alias_value":"KQP6M6T3","created_at":"2026-05-18T12:32:33Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:KQP6M6T3JM3ECZV4MB3PGYHNGA","target":"record","payload":{"canonical_record":{"source":{"id":"1804.06661","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"nucl-ex","submitted_at":"2018-04-18T11:40:37Z","cross_cats_sorted":[],"title_canon_sha256":"40616f2407fc720aaaba20e1636bc68cb02b27044b65eda9263f739d29287d83","abstract_canon_sha256":"06dbd31e2ad7e24e150f110c299142c65b816ceedc16072d483759dd6288c502"},"schema_version":"1.0"},"canonical_sha256":"541fe67a7b4b364166bc6076f360ed3008f31c48f88f4558b2b766f7c7f8b306","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:13:26.174663Z","signature_b64":"TfhShP94RuANpV1VLiUdF7oERRcacrJYCR03YiO6gyCrUELmPZ3NusbcItsnAEwfCZ2nR7Vr9reU/rXlkDKAAQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"541fe67a7b4b364166bc6076f360ed3008f31c48f88f4558b2b766f7c7f8b306","last_reissued_at":"2026-05-18T00:13:26.173957Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:13:26.173957Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1804.06661","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":"2026-05-18T00:13:26Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"mCoonlQGtVZ4GEC/BxxlDdRNfoFsWjGoi2V0hLog0hlOKX127JmDNQMyubDfJhTHYaQor6U9JyNuBCpOqEpXBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-12T09:50:59.956110Z"},"content_sha256":"70001562d2f5aa9be99ba5540e51c1ecf40ff69eb69d88a056d7ed5cc4198d49","schema_version":"1.0","event_id":"sha256:70001562d2f5aa9be99ba5540e51c1ecf40ff69eb69d88a056d7ed5cc4198d49"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:KQP6M6T3JM3ECZV4MB3PGYHNGA","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Positron Beams and Two-Photon Exchange: The Key to Precision Form Factors","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"Jan C. Bernauer","submitted_at":"2018-04-18T11:40:37Z","abstract_excerpt":"The proton elastic form factor ratio can be measured either via Rosenbluth separation in an unpolarized beam and target experiment, or via the use of polarization degrees of freedom. However, data produced by these two approaches show a discrepancy, increasing with $Q^2$. The proposed explanation of this discrepancy---two-photon exchange---has been tested recently by three experiments. The results support the existence of a small two-photon exchange effect but cannot establish that theoretical treatment at the measured momentum transfers are valid. At larger momentum transfers, theory remains "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1804.06661","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":"2026-05-18T00:13:26Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"0TsJbNnjv+8RsMHL6vx0bo2GTcCXrB1+C2U1z6b6swlQDKCOSC3fwtYqWuiJmn9f3ei0ALz1qAevv6YXWLi8Dw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-12T09:50:59.956684Z"},"content_sha256":"d3115154627df36d0e33ca4254deab89480b7b3632f472135d60c403837fdcd2","schema_version":"1.0","event_id":"sha256:d3115154627df36d0e33ca4254deab89480b7b3632f472135d60c403837fdcd2"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/KQP6M6T3JM3ECZV4MB3PGYHNGA/bundle.json","state_url":"https://pith.science/pith/KQP6M6T3JM3ECZV4MB3PGYHNGA/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/KQP6M6T3JM3ECZV4MB3PGYHNGA/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":"2026-06-12T09:50:59Z","links":{"resolver":"https://pith.science/pith/KQP6M6T3JM3ECZV4MB3PGYHNGA","bundle":"https://pith.science/pith/KQP6M6T3JM3ECZV4MB3PGYHNGA/bundle.json","state":"https://pith.science/pith/KQP6M6T3JM3ECZV4MB3PGYHNGA/state.json","well_known_bundle":"https://pith.science/.well-known/pith/KQP6M6T3JM3ECZV4MB3PGYHNGA/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:KQP6M6T3JM3ECZV4MB3PGYHNGA","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":"06dbd31e2ad7e24e150f110c299142c65b816ceedc16072d483759dd6288c502","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"nucl-ex","submitted_at":"2018-04-18T11:40:37Z","title_canon_sha256":"40616f2407fc720aaaba20e1636bc68cb02b27044b65eda9263f739d29287d83"},"schema_version":"1.0","source":{"id":"1804.06661","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1804.06661","created_at":"2026-05-18T00:13:26Z"},{"alias_kind":"arxiv_version","alias_value":"1804.06661v1","created_at":"2026-05-18T00:13:26Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1804.06661","created_at":"2026-05-18T00:13:26Z"},{"alias_kind":"pith_short_12","alias_value":"KQP6M6T3JM3E","created_at":"2026-05-18T12:32:33Z"},{"alias_kind":"pith_short_16","alias_value":"KQP6M6T3JM3ECZV4","created_at":"2026-05-18T12:32:33Z"},{"alias_kind":"pith_short_8","alias_value":"KQP6M6T3","created_at":"2026-05-18T12:32:33Z"}],"graph_snapshots":[{"event_id":"sha256:d3115154627df36d0e33ca4254deab89480b7b3632f472135d60c403837fdcd2","target":"graph","created_at":"2026-05-18T00:13:26Z","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 proton elastic form factor ratio can be measured either via Rosenbluth separation in an unpolarized beam and target experiment, or via the use of polarization degrees of freedom. However, data produced by these two approaches show a discrepancy, increasing with $Q^2$. The proposed explanation of this discrepancy---two-photon exchange---has been tested recently by three experiments. The results support the existence of a small two-photon exchange effect but cannot establish that theoretical treatment at the measured momentum transfers are valid. At larger momentum transfers, theory remains ","authors_text":"Jan C. Bernauer","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"nucl-ex","submitted_at":"2018-04-18T11:40:37Z","title":"Positron Beams and Two-Photon Exchange: The Key to Precision Form Factors"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1804.06661","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":"sha256:70001562d2f5aa9be99ba5540e51c1ecf40ff69eb69d88a056d7ed5cc4198d49","target":"record","created_at":"2026-05-18T00:13:26Z","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":"06dbd31e2ad7e24e150f110c299142c65b816ceedc16072d483759dd6288c502","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"nucl-ex","submitted_at":"2018-04-18T11:40:37Z","title_canon_sha256":"40616f2407fc720aaaba20e1636bc68cb02b27044b65eda9263f739d29287d83"},"schema_version":"1.0","source":{"id":"1804.06661","kind":"arxiv","version":1}},"canonical_sha256":"541fe67a7b4b364166bc6076f360ed3008f31c48f88f4558b2b766f7c7f8b306","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"541fe67a7b4b364166bc6076f360ed3008f31c48f88f4558b2b766f7c7f8b306","first_computed_at":"2026-05-18T00:13:26.173957Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:13:26.173957Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"TfhShP94RuANpV1VLiUdF7oERRcacrJYCR03YiO6gyCrUELmPZ3NusbcItsnAEwfCZ2nR7Vr9reU/rXlkDKAAQ==","signature_status":"signed_v1","signed_at":"2026-05-18T00:13:26.174663Z","signed_message":"canonical_sha256_bytes"},"source_id":"1804.06661","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:70001562d2f5aa9be99ba5540e51c1ecf40ff69eb69d88a056d7ed5cc4198d49","sha256:d3115154627df36d0e33ca4254deab89480b7b3632f472135d60c403837fdcd2"],"state_sha256":"45c64d5eee5da17a2ad216d6f1f2cdffecca5827e2bda961aadda5e0abeac0cf"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"7MdI6zmRF19GjfNekO6hG67gNvMfHEBNwS3z0TvkYDe3dk1LZzMlRk3wRpHJb+mFkslDd+jxi1NWoxssi/GrAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-12T09:50:59.958647Z","bundle_sha256":"1addac3d512f230831282d09659f3c03ed893344265fb5ff00e4c8c71a800e0c"}}