{"paper":{"title":"Stellar limits on scalars from electron-nucleus bremsstrahlung","license":"http://creativecommons.org/publicdomain/zero/1.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"hep-ph","authors_text":"Andrea Caputo, Edoardo Vitagliano, Georg Raffelt, Salvatore Bottaro","submitted_at":"2023-03-01T19:05:41Z","abstract_excerpt":"We revisit stellar energy-loss bounds on the Yukawa couplings $g_{\\rm B,L}$ of baryophilic and leptophilic scalars $\\phi$. The white-dwarf luminosity function yields $g_{\\rm B}\\lesssim 7 \\times 10^{-13}$ and $g_{\\rm L}\\lesssim 4 \\times 10^{-16}$, based on bremsstrahlung from ${}^{12}{\\rm C}$ and ${}^{16}{\\rm O}$ collisions with electrons. In models with a Higgs portal, this also implies a bound on the scalar-Higgs mixing angle $\\sin \\theta \\lesssim 2 \\times 10^{-10}$. Our new bounds apply for $m_\\phi\\lesssim {\\rm 1~keV}$ and are among the most restrictive ones, whereas for $m_\\phi\\lesssim 0.5\\"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2303.00778","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/2303.00778/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"}