{"paper":{"title":"Chiral dynamics, S-wave contributions and angular analysis in $D\\to \\pi\\pi \\ell\\bar\\nu$","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ex"],"primary_cat":"hep-ph","authors_text":"Shuai Zhao, Wei Wang, Yu-Ji Shi","submitted_at":"2017-01-26T04:06:45Z","abstract_excerpt":"We present a theoretical analysis of the $D^-\\to \\pi^+\\pi^- \\ell\\bar\\nu$ and $\\bar D^0\\to \\pi^+\\pi^0 \\ell\\bar\\nu$ decays. We construct a general angular distribution which can include arbitrary partial waves of $\\pi\\pi$. Retaining the S-wave and P-wave contributions we study the branching ratios, forward--backward asymmetries and a few other observables. The P-wave contribution is dominated by $\\rho^0$ resonance, and the S-wave contribution is analyzed using the unitarized chiral perturbation theory. The obtained branching fraction for $D\\to \\rho\\ell\\nu$, at the order $10^{-3}$, is consistent "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1701.07571","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"}