{"paper":{"title":"The Chiral Lagrangian parameters, $\\overline{\\ell}_1$, $\\overline{\\ell}_2$, are determined by the $\\rho$--resonance","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ph","authors_text":"J. Portoles, M.R. Pennington","submitted_at":"1994-09-27T22:18:57Z","abstract_excerpt":"The all--important consequence of Chiral Dynamics for $\\pi \\pi$ scattering is the Adler zero, which forces $\\pi \\pi$ amplitudes to grow asymptotically. The continuation of this subthreshold zero into the physical regions requires a $P$--wave resonance, to be identified with the $\\rho$. It is a feature of $\\pi \\pi$ scattering that convergent dispersive integrals for the $I=1$ channel are essentially saturated by the $\\rho$--resonance and are much larger than those with $I=2$ quantum numbers. These facts predict the parameters $\\overline{\\ell}_1$, $\\overline{\\ell}_2$ of the Gasser--Leutwyler Chi"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"hep-ph/9409426","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/hep-ph/9409426/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"}