{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:VBRQ2WDJ7AQ3R3LCSCHVWEGR42","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":"9651f17d2457463d9edb26636bb99143928e86810bb58948c8622bc615fabc50","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2018-05-10T17:36:18Z","title_canon_sha256":"abbb95c686fad963bcc37de6f83f0eb50453cefdc3be39f03cffd2fbe8edb39f"},"schema_version":"1.0","source":{"id":"1805.04080","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1805.04080","created_at":"2026-05-18T00:00:55Z"},{"alias_kind":"arxiv_version","alias_value":"1805.04080v2","created_at":"2026-05-18T00:00:55Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1805.04080","created_at":"2026-05-18T00:00:55Z"},{"alias_kind":"pith_short_12","alias_value":"VBRQ2WDJ7AQ3","created_at":"2026-05-18T12:32:59Z"},{"alias_kind":"pith_short_16","alias_value":"VBRQ2WDJ7AQ3R3LC","created_at":"2026-05-18T12:32:59Z"},{"alias_kind":"pith_short_8","alias_value":"VBRQ2WDJ","created_at":"2026-05-18T12:32:59Z"}],"graph_snapshots":[{"event_id":"sha256:9447a7d846c42317481888510ca8e04146b54b449086ecf36ccda086a06fbcd6","target":"graph","created_at":"2026-05-18T00:00:55Z","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":"There are multiple techniques to determine the chemical composition of the ultra-high-energy cosmic rays. While most of the methods are primarily sensitive to the average atomic mass, it is challenging to discriminate between the two lightest elements: proton and helium. In this paper, the proton-to-helium ratio in the energy range $10^{18.0} \\mbox{eV}$ to $10^{19.3} \\mbox{eV}$ is estimated using the tail of the distribution of the depth of the shower maximum $X_{\\mathrm{max}}$. Using the exponential decay scale $\\Lambda$ measured by the Pierre Auger Observatory and the Telescope Array experim","authors_text":"Grigory I. Rubtsov, Ivan S. Karpikov, Yana V. Zhezher","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2018-05-10T17:36:18Z","title":"Lower limit on the ultra-high-energy proton-to-helium ratio from the measurements of the tail of $X_{\\mathrm{max}}$ distribution"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1805.04080","kind":"arxiv","version":2},"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":"sha256:84dba7b31fbc13e58a92a42a2ea38f73b4fd2b4c2f11c1929e3f9f356e460cf4","target":"record","created_at":"2026-05-18T00:00:55Z","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":"9651f17d2457463d9edb26636bb99143928e86810bb58948c8622bc615fabc50","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2018-05-10T17:36:18Z","title_canon_sha256":"abbb95c686fad963bcc37de6f83f0eb50453cefdc3be39f03cffd2fbe8edb39f"},"schema_version":"1.0","source":{"id":"1805.04080","kind":"arxiv","version":2}},"canonical_sha256":"a8630d5869f821b8ed62908f5b10d1e69bc0d747174070a8f716b637173b3972","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"a8630d5869f821b8ed62908f5b10d1e69bc0d747174070a8f716b637173b3972","first_computed_at":"2026-05-18T00:00:55.962405Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:00:55.962405Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"PYUokCI01j7YFKD+7c0YdOSvoiNdGPKjKyi6/cFrgXoYnKU2qZam7C7lSsKvcssRBmEY6Ocl2S/qTZdFvr9zBQ==","signature_status":"signed_v1","signed_at":"2026-05-18T00:00:55.963188Z","signed_message":"canonical_sha256_bytes"},"source_id":"1805.04080","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:84dba7b31fbc13e58a92a42a2ea38f73b4fd2b4c2f11c1929e3f9f356e460cf4","sha256:9447a7d846c42317481888510ca8e04146b54b449086ecf36ccda086a06fbcd6"],"state_sha256":"7e929b08b274af3366ddb951621ea9bb5e35dbda0855df66d309fa85f2c4b149"}