{"paper":{"title":"On the second Gegenbauer moment of $\\rho$-meson distribution amplitude","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ex","hep-lat"],"primary_cat":"hep-ph","authors_text":"Hyeon-Dong Son, Maxim V. Polyakov","submitted_at":"2020-08-14T09:53:45Z","abstract_excerpt":"Using the soft pion theorem, crossing, and the dispersion relations for the two pion distribution amplitude ($2\\pi$DA) we argue that the second Gegenbauer moment the $\\rho$-meson DA ($a_2^{(\\rho)}$) most probably is negative. This result is at variance with the majority of the model calculations for $a_2^{(\\rho)}$.\n  Using the instanton theory of the QCD vacuum, we computed $a_2^{(\\rho)}$ at a low normalisation point and obtain for the ratio $ a_2^{(\\rho)}/M_3^{(\\pi)}$ {\\it definitely negative value} in the range of $a_2^{(\\rho)}/M_3^{(\\pi)}\\in [-2, -1]$. The range of values corresponds to a g"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2008.06270","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/2008.06270/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"}