{"paper":{"title":"Pion decay constraints on exotic 17 MeV vector bosons","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["hep-ex"],"primary_cat":"hep-ph","authors_text":"Matheus Hostert, Maxim Pospelov","submitted_at":"2023-06-26T21:25:16Z","abstract_excerpt":"We derive constraints on the couplings of light vector particles to all first-generation Standard Model fermions using leptonic decays of the charged pion, $\\pi^+\\to e^+ \\nu_e X_\\mu$. In models where the net charge to which $X_\\mu$ couples is not conserved, no lepton helicity flip is required for the decay to happen, enhancing the decay rate by factors of ${O}(m_\\pi^4/m_e^2m_X^2)$. A past search at the SINDRUM-I spectrometer severely constrains this possibility. In the context of the hypothesized $17$ MeV particle proposed to explain anomalous $^8$Be, $^4$He, and $^{12}$C nuclear transitions c"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2306.15077","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/2306.15077/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"}