{
  "abstract": "A search for a Majorana-type heavy neutral lepton (HNL) produced in top quark decays is reported. The search is based on proton-proton collision data at $\\sqrt{s}$ = 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$, collected during 2016$-$2018 with the CMS detector at the CERN LHC. In the type-I seesaw model, a Majorana HNL can mediate lepton-number-violating top quark decays. The search targets top quark pair production events in which one top quark decays into a bottom quark and a W boson, which subsequently decays into a charged lepton (electron or muon) and an HNL. The Majorana HNL then decays into a W boson and a charged lepton with the same sign and flavor as the one produced with the HNL. The experimental signature features a same-sign, same-flavor lepton pair and jets. The HNL masses between 20 and 100 GeV are probed. The data agree with the standard model background prediction. Observed (expected) upper limits at 95% confidence level are set on the branching fraction of the top quark decay into an HNL, a charged lepton, and a bottom quark, varying between [1.1 (0.71)] $\\times$10$^{-5}$ and [4.8 (3.0)] $\\times$10$^{-5}$ in the dielectron channel, and between [3.7 (3.4)] $\\times$10$^{-6}$ and [2.4 (1.3)] $\\times$10$^{-5}$ in the dimuon channel.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.04904",
  "author_total": 1,
  "authors": [
    {
      "name": "CMS Collaboration"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cyammk61fh23s.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.04904",
  "fulltext_url": null,
  "id": "cyammk61fh23s",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.04904",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "hep-ex"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.04904",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cyammk61fh23s.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T15:21:25Z",
      "native_id": "2611.04904",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.04904"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Search for heavy neutral leptons in top quark decays with same-sign, same-flavor dilepton final states in proton-proton collisions at $\\sqrt{s}$ = 13 TeV",
  "title_text": "Search for heavy neutral leptons in top quark decays with same-sign, same-flavor dilepton final states in proton-proton collisions at √s = 13 TeV",
  "type": "preprint",
  "updated_at": "2026-11-06T18:21:01Z",
  "url": "https://research.draconitic.com/paper/cyammk61fh23s",
  "venue": "arXiv",
  "versions": []
}