{"paper":{"title":"Geometry of particle emission in UrQMD Ar+Sc collisions at SPS energies","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Simulations of Ar+Sc collisions at SPS energies show two-pion pair sources follow Lévy-stable distributions whose parameters map to spatial scale, shape, and emission strength.","cross_cats":["nucl-th"],"primary_cat":"hep-ph","authors_text":"Barnabas Porfy, Mate Csanad","submitted_at":"2025-12-04T17:34:21Z","abstract_excerpt":"Over the past few decades, progress in femtoscopy has been driven by the interplay between experimental measurements and theoretical calculations. Measurements provide data to support the theory, while theoretical predictions guide new measurements. In the recent decade, several experiments have confirmed that the two-particle pion-emitting source is well described by L\\'evy alpha-stable distributions. To enable theoretical interpretation, phenomenological simulations have been done at RHIC and LHC energies, in large systems such as Au+Au or Pb+Pb, using various available heavy-ion collision m"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We find that the pair source can be described with Lévy-stable distributions. We subsequently interpret the physical meaning of the extracted Lévy parameters corresponding to the spatial scale, shape, and strength of the source.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the UrQMD Monte Carlo generator, after validation against hadronic spectra, produces realistic two-pion source distributions that can be directly compared to experimental femtoscopy measurements in Ar+Sc collisions.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"UrQMD simulations demonstrate that pion pair sources in Ar+Sc collisions at SPS energies are described by Lévy alpha-stable distributions, establishing a theoretical baseline for intermediate systems.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Simulations of Ar+Sc collisions at SPS energies show two-pion pair sources follow Lévy-stable distributions whose parameters map to spatial scale, shape, and emission strength.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"0c63b2427df8cbea7325cb887f0dea8edfb6f25b53f3b308e2aa6f0ff4ddbc5b"},"source":{"id":"2512.05019","kind":"arxiv","version":2},"verdict":{"id":"b4204ab6-d329-44ad-b4de-8c8a78e5391a","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-17T01:22:18.168019Z","strongest_claim":"We find that the pair source can be described with Lévy-stable distributions. We subsequently interpret the physical meaning of the extracted Lévy parameters corresponding to the spatial scale, shape, and strength of the source.","one_line_summary":"UrQMD simulations demonstrate that pion pair sources in Ar+Sc collisions at SPS energies are described by Lévy alpha-stable distributions, establishing a theoretical baseline for intermediate systems.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the UrQMD Monte Carlo generator, after validation against hadronic spectra, produces realistic two-pion source distributions that can be directly compared to experimental femtoscopy measurements in Ar+Sc collisions.","pith_extraction_headline":"Simulations of Ar+Sc collisions at SPS energies show two-pion pair sources follow Lévy-stable distributions whose parameters map to spatial scale, shape, and emission strength."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2512.05019/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":34,"sample":[{"doi":"","year":1959,"title":"G. Goldhaber, W. B. Fowler, S. Goldhaber, and T. F. Hoang. Pion-pion correlations in antiproton annihi- lation events.Phys. Rev. Lett., 3:181, 1959","work_id":"41902b4e-2329-4d66-aa12-d066d4180726","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1960,"title":"G. Goldhaber, S. Goldhaber, W.-Y. Lee, and A. Pais. Influence of Bose-Einstein statistics on the anti-proton proton annihilation process.Phys. Rev., 120:300, 1960","work_id":"172d3c3a-0a42-48b8-9284-3df5a22f0079","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1997,"title":"D. A. Brown and P. Danielewicz. Imaging of sources in heavy ion reactions.Phys. Lett. B, 398:252–258, 1997","work_id":"0a40934f-5f83-4b01-9eb7-a46bc106d695","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2007,"title":"S. S. Adler et al. Evidence for a long-range component in the pion emission source in Au + Au collisions at √sN N = 200 GeV.Phys. Rev. Lett., 98:132301, 2007","work_id":"09942216-0d41-49a5-aac4-99a84fca21e3","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2018,"title":"A. Adare et al. L´ evy-stable two-pion Bose-Einstein correlations in √sN N = 200 GeV Au+Au collisions. Phys. Rev. C, 97(6):064911, 2018. [Erratum: Phys.Rev.C 108, 049905 (2023)]","work_id":"f90c2b78-8a66-43c3-a94f-9da38a4f8c2e","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":34,"snapshot_sha256":"bc54418b59c17ac9fea535c2029a5d070e78bf36255997162cebda76511e3103","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"01f46612b9a7139180194a0620ac3248696d0ec0a86f4578ff633a0ee6c6de18"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}