{"paper":{"title":"First extraction of the proton mass radius and scattering length $\\left|\\alpha_{\\rho^0 p}\\right| $ from $\\rho^0$ photoproduction","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"nucl-th","authors_text":"Fancong Zeng, Li Zhang, Quanjin Wang, Xiao-Yun Wang","submitted_at":"2022-06-18T10:22:52Z","abstract_excerpt":"As it involves the lightest physical states excited from the vacuum by the vector quark current, near-threshold $\\rho^0$ photoproduction is considered a possible way to research the proton radius and the absolute value of the scattering lengths of the $\\rho^0$--proton interaction. In this work, under the assumption of a scalar form factor of dipole form, the value of the proton mass radius is calculated as $0.85\\pm 0.06 \\text{ fm }$ by fitting the differential cross section of the $\\gamma p \\rightarrow \\rho^0 p$ reaction at near-threshold energy. For light vector meson photoproduction, because"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2206.09170","kind":"arxiv","version":3},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2206.09170/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}