{"paper":{"title":"First Observation of the $\\Lambda(1405)$ Line Shape in Electroproduction","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ex","nucl-th"],"primary_cat":"nucl-ex","authors_text":"CLAS Collaboration, H.Y. Lu, R.A. Schumacher","submitted_at":"2013-07-16T20:02:30Z","abstract_excerpt":"We report the first observation of the line shape of the $\\Lambda(1405)$ from electroproduction, and show that it is not a simple Breit-Wigner resonance. Electroproduction of $K^+ \\Lambda(1405)$ off the proton was studied by using data from CLAS at Jefferson Lab in the range $1.0<Q^2<3.0$ (GeV/c)$^2$. The analysis utilized the decay channels $\\Sigma^+ \\pi^-$ of the $\\Lambda(1405)$ and $p \\pi^0$ of the $\\Sigma^+$. Neither the standard (PDG) resonance parameters, nor free parameters fitting to a single Breit-Wigner resonance represent the line shape. In our fits, the line shape corresponds appro"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1307.4411","kind":"arxiv","version":2},"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"}