{
  "abstract": "The neutrino mass ordering remains unresolved because long-baseline oscillation measurements are entangled with the unknown CP phase $δ_{CP}$; a collider probe free of this degeneracy would provide a qualitatively different, complementary test. We show that when the long-lived charged particle producing a displaced-lepton signal at the High-Luminosity LHC is also the mediator responsible for Majorana neutrino masses---the \\textit{shared-coupling condition}---the Casas--Ibarra parametrization determines the lepton flavor ratio $N_e/N_μ$ of time-delayed leptons in terms of Pontecorvo--Maki--Nakagawa--Sakata (PMNS) mixing parameters alone. Within the resulting \\textit{shared-coupling class} of models the ratio is fixed by oscillation data, independent of all beyond-Standard-Model mass and coupling parameters up to calculable corrections bounded by charged-lepton-flavor-violation data, yielding $N_e/N_μ= 0.140$ for the Normal and $2.11$ for the Inverted Hierarchy---a separation of more than an order of magnitude between the two predictions. This prediction holds identically across the Scotogenic model, the Type-III seesaw, the inverse and linear seesaw, and lepton-portal dark matter, and is stable against oscillation-parameter uncertainties and detector-efficiency variations, which cancel in the ratio. A single efficiency-corrected decision criterion identifies the hierarchy, and explicit signal-yield estimates combined with an exact Poisson test show that $\\mathcal{O}(25)$ displaced-lepton events suffice for a $3σ$ discrimination with the timing infrastructure already under construction at CMS and ATLAS---so that a positive long-lived-particle signal would simultaneously resolve the mass ordering, with no dependence on $δ_{CP}$.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: Chin. Phys. C 51, 011002 (2027)",
  "arxiv": "2609.04761",
  "author_total": 1,
  "authors": [
    {
      "name": "Renjie Wang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/32btn6x65sewv.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.04761",
  "fulltext_url": null,
  "id": "32btn6x65sewv",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.04761",
  "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"
    ],
    [
      "arxiv",
      "hep-ph"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2609.04761",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/32btn6x65sewv.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:25Z",
      "native_id": "2609.04761",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.04761"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Flavor Tomography of Long-Lived Neutrino-Mass Mediators: Probing the Neutrino Mass Ordering at the HL-LHC",
  "title_text": "Flavor Tomography of Long-Lived Neutrino-Mass Mediators: Probing the Neutrino Mass Ordering at the HL-LHC",
  "type": "preprint",
  "updated_at": "2026-11-08T21:20:26Z",
  "url": "https://research.draconitic.com/paper/32btn6x65sewv",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1088/1674-1137/aea53f",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}