{"paper":{"title":"Impact of the $a_1(1260) \\pi$ cascade contribution on $D^0 \\to \\pi^+ \\pi^- \\ell^+ \\ell^-$ decays","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["hep-ex"],"primary_cat":"hep-ph","authors_text":"Eleftheria Solomonidi, Luiz Vale Silva","submitted_at":"2025-11-04T17:59:08Z","abstract_excerpt":"We revisit the Standard Model description of the recently measured rare decays $D^0\\to\\pi^+\\pi^-\\ell^+\\ell^-$. Because of the effectiveness of the Glashow-Iliopoulos-Maiani mechanism in charm flavour-changing neutral currents, those decays are driven by non-local insertions of four-quark operators. Following previous work, we consider the mediation of resonances both for the dipion and dilepton pairs. For the first time, we incorporate the effect of the cascade-type topology $D^0\\to \\pi^- a_1^+(1260)(\\to\\pi^+\\rho^0(\\to\\ell^+\\ell^-))$, which manifests distinctly in the invariant-mass and angula"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2511.02775","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/2511.02775/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"}