{"paper":{"title":"Triangle singularity in $\\tau^- \\to \\nu_\\tau \\pi^- f_0(980)$ ($a_0(980)$) decays","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ph","authors_text":"E. Oset, L. R. Dai, Q. X. Yu","submitted_at":"2018-09-28T13:07:56Z","abstract_excerpt":"We study the triangle mechanism for the decay $\\tau^- \\to \\nu_\\tau \\pi^- f_0(980)$, with the $f_0(980)$ decaying into $\\pi^+ \\pi^- $. This process is initiated by $\\tau^- \\to \\nu_\\tau K^{*0} K^-$ followed by the $K^{*0}$ decay into $\\pi^- K^+$, then the $K^- K^+$ produce the $f_0(980)$ through a triangle loop containing $ K^* K^+ K^-$ which develops a singularity around $1420$~MeV in the $\\pi f_0(980)$ invariant mass. We find a narrow peak in the $\\pi^+ \\pi^-$ invariant mass distribution, which originates from the $f_0(980)$ amplitude. Similarly, we also study the triangle mechanism for the de"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1809.11007","kind":"arxiv","version":1},"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"}