{"paper":{"title":"Role of heavy neutral lepton in lepton number violating $B$ meson decays","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Heavy neutral leptons mediate lepton-number violating B and B_c decays with branching ratios up to 10^{-8}.","cross_cats":[],"primary_cat":"hep-ph","authors_text":"Dhiren Panda, Manas Kumar Mohapatra, Rukmani Mohanta","submitted_at":"2026-04-27T10:51:20Z","abstract_excerpt":"We study the phenomenology of heavy neutral leptons (HNLs) in $B$-meson decays as probes of physics beyond the Standard Model. Focusing on the leptonic channels $B \\to \\mu N$ and $B \\to \\tau N$, we constrain the allowed regions in the $M_N$--$|U_{\\ell N}|^2$ plane using current experimental data. Using these constraints, we investigate lepton-number violating ($\\Delta L=2$) processes mediated by on-shell HNLs, including $B_{(c)}^- \\to \\pi^+ \\mu^- \\mu^-$ and $B_c^- \\to J/\\psi\\, \\pi^+ \\mu^- \\mu^-$. For benchmark values $|U_{\\mu N}|^2 = 10^{-6}$ and $M_N = 2$-- $3\\,\\mathrm{GeV}$, the predicted br"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"For benchmark values |U_μN|^2 = 10^{-6} and M_N = 2--3 GeV, the predicted branching ratios lie in the range O(10^{-13})--O(10^{-8}). Among the channels, B_c^- → π^+ μ^- μ^- shows the largest enhancement, while B_c^- → J/ψ π^+ μ^- μ^- is strongly suppressed.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That heavy neutral leptons are produced on-shell and mediate the lepton-number violating processes in the listed B and B_c decay channels, with mixing parameters taken from the regions allowed by B → μN and B → τN data.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Heavy neutral leptons with masses of 2-3 GeV and mixing |U_μN|^2 = 10^{-6} can produce lepton-number violating B decays with branching ratios from 10^{-13} to 10^{-8}, with the largest signals in B_c^- → π^+ μ^- μ^-.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Heavy neutral leptons mediate lepton-number violating B and B_c decays with branching ratios up to 10^{-8}.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"640ddd8b8ddaf2622cd5591dfbb5fb7a9c47de87e1a46abc5e0a0a619ea64a98"},"source":{"id":"2604.24305","kind":"arxiv","version":2},"verdict":{"id":"825833b6-19af-496c-acd2-d8c0e61d88b9","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-08T03:13:05.131477Z","strongest_claim":"For benchmark values |U_μN|^2 = 10^{-6} and M_N = 2--3 GeV, the predicted branching ratios lie in the range O(10^{-13})--O(10^{-8}). Among the channels, B_c^- → π^+ μ^- μ^- shows the largest enhancement, while B_c^- → J/ψ π^+ μ^- μ^- is strongly suppressed.","one_line_summary":"Heavy neutral leptons with masses of 2-3 GeV and mixing |U_μN|^2 = 10^{-6} can produce lepton-number violating B decays with branching ratios from 10^{-13} to 10^{-8}, with the largest signals in B_c^- → π^+ μ^- μ^-.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That heavy neutral leptons are produced on-shell and mediate the lepton-number violating processes in the listed B and B_c decay channels, with mixing parameters taken from the regions allowed by B → μN and B → τN data.","pith_extraction_headline":"Heavy neutral leptons mediate lepton-number violating B and B_c decays with branching ratios up to 10^{-8}."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.24305/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"ai_meta_artifact","ran_at":"2026-05-21T07:34:12.110454Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-19T22:15:35.769993Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"7e717a2dd7d6d559176e2690b05953095de1ef19e19db107ebc9c82223f4c84e"},"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"}