{"paper":{"title":"Form factors of the $\\rho$ meson from effective field theory and the lattice","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"A background electromagnetic field plus the Feynman-Hellmann theorem yields first estimates of the three form factors of the rho meson in effective field theory.","cross_cats":["hep-ph","nucl-th"],"primary_cat":"hep-lat","authors_text":"Ajay S. Sakthivasan, Akaki Rusetsky, Gerrit Schierholz, Jia-Jun Wu, Ulf-G. Mei{\\ss}ner","submitted_at":"2026-02-26T14:27:52Z","abstract_excerpt":"The calculation of resonance form factors in effective field theory as well as on the lattice is a highly challenging task. In a recent paper, we proposed a novel method based on the introduction of a background field and the Feynman-Hellmann theorem to address the problem, and applied it to a toy model. In the present work we use this method for the electromagnetic form factors of the $\\rho$-meson. By matching the results to Chiral Perturbation Theory, we provide a first, crude estimate of all three form factors of the $\\rho$-meson within the effective field theory. Contact contributions to t"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"By matching the results to Chiral Perturbation Theory, we provide a first, crude estimate of all three form factors of the ρ-meson within the effective field theory. Contact contributions to these form factors turn out to be substantial.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The background-field plus Feynman-Hellmann procedure, validated only on a toy model, extends without major modification to the interacting rho-meson system in effective field theory, and the subsequent matching to chiral perturbation theory faithfully extracts the physical form factors.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Background-field plus Feynman-Hellmann method in effective field theory yields first crude estimates of the rho meson's three electromagnetic form factors, with substantial contact contributions.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"A background electromagnetic field plus the Feynman-Hellmann theorem yields first estimates of the three form factors of the rho meson in effective field theory.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"7a98d519bf70382ad8ba0906da12bc0e6b6a6cf5b54aaafd9aa52ffb10661a6b"},"source":{"id":"2602.23044","kind":"arxiv","version":2},"verdict":{"id":"8aaaddd7-a834-4b14-b089-c398cf4c577e","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-15T19:19:19.979474Z","strongest_claim":"By matching the results to Chiral Perturbation Theory, we provide a first, crude estimate of all three form factors of the ρ-meson within the effective field theory. Contact contributions to these form factors turn out to be substantial.","one_line_summary":"Background-field plus Feynman-Hellmann method in effective field theory yields first crude estimates of the rho meson's three electromagnetic form factors, with substantial contact contributions.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The background-field plus Feynman-Hellmann procedure, validated only on a toy model, extends without major modification to the interacting rho-meson system in effective field theory, and the subsequent matching to chiral perturbation theory faithfully extracts the physical form factors.","pith_extraction_headline":"A background electromagnetic field plus the Feynman-Hellmann theorem yields first estimates of the three form factors of the rho meson in effective field theory."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2602.23044/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":58,"sample":[{"doi":"","year":2022,"title":"Meißner, Fernando Romero-L´ opez, Akaki Rusetsky, and Gerrit Schierholz","work_id":"2f4bf72d-52e0-4733-9651-db14c4c6c600","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2008,"title":"Gurtler et al","work_id":"15c436a1-f928-4b4b-8efd-3098db717b6c","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2009,"title":"C. Alexandrou, T. Korzec, G. Koutsou, Th. Leontiou, C. Lorce, J. W. Negele, V. Pascalutsa, A. Tsapalis, and M. Vanderhaeghen. ∆-baryon electromagnetic form factors in lattice QCD. Phys. Rev. D, 79:014","work_id":"7fa526aa-1b0e-4579-a936-9e204564e04a","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2020,"title":"Stokes, Waseem Kamleh, and Derek B","work_id":"dda91746-0ac2-48fe-b373-722de9a7bb66","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2017,"title":"Jonathan M. M. Hall, Waseem Kamleh, Derek B. Leinweber, Benjamin J. Menadue, Benjamin J. Owen, and Anthony W. Thomas. Light-quark contributions to the magnetic form factor of the Λ (1405).Phys. Rev. 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