{
  "abstract": "We present a unified analysis of two matter-potential systematics in long-baseline (LBL) neutrino oscillation experiments. Matter-induced extrinsic CPT violation produces a non-zero asymmetry $A_{μe}^{CPT} = (P_{μe} - P_{\\barμ\\bar{e}})/(P_{μe} + P_{\\barμ\\bar{e}})$, computed here with exact three-flavour matrix-exponentiation propagators for T2K, NO$ν$A, DUNE, and Hyper-Kamiokande; values range from 0.022 to 0.180 at the respective peak energies and differ by up to 9\\% between normal and inverted mass orderings. The three-dimensional surface $A_{μe}^{CPT}(E, δ_{CP})$ at the DUNE baseline reveals an entanglement between extrinsic CPT violation and intrinsic CP violation in the high-$L/E$ regime that requires joint statistical treatment. Concurrently, replacing the Preliminary Reference Earth Model (PREM) with a constant path-averaged density introduces a $δ_{CP}$-reconstruction bias below $0.3^{\\circ}$ for $L \\leq 5000$ km but growing to $17.8^{\\circ}$ at $L = 7000$ km and $172.2^{\\circ}$ at $L = 12000$ km. Since both effects share the same matter-potential Hamiltonian they must be modelled jointly; a Poisson log-likelihood $χ^2$ statistic with nuisance-parameter pull terms is used to quantify the bias.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.00436",
  "author_total": 4,
  "authors": [
    {
      "name": "Tia Pandit"
    },
    {
      "name": "Bipin Singh Koranga"
    },
    {
      "name": "Aditya Pant"
    },
    {
      "name": "Vivek Kumar Nautiyal"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/c1f0gxav1fx82.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.00436",
  "fulltext_url": null,
  "id": "c1f0gxav1fx82",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.00436",
  "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-ph"
    ],
    [
      "openalex",
      "3106|Neutrino Physics Research"
    ]
  ],
  "openalex": "W7172444242",
  "pdf_url": "https://arxiv.org/pdf/2608.00436",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-13",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/c1f0gxav1fx82.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:25Z",
      "native_id": "2608.00436",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.00436"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Matter-Induced CPT Violation and Earth-Density Stratification Effects in Long-Baseline Neutrino Oscillation Experiments",
  "title_text": "Matter-Induced CPT Violation and Earth-Density Stratification Effects in Long-Baseline Neutrino Oscillation Experiments",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:25Z",
  "url": "https://research.draconitic.com/paper/c1f0gxav1fx82",
  "venue": "arXiv",
  "versions": []
}