{
  "abstract": "Breaking of $SU(5)$ down to the Standard Model gauge group can be implemented by any non-trivial self-conjugate scalar representation with a suitable vacuum expectation value. The Georgi-Glashow model accomplishes this breaking with a 24-dimensional representation. That choice, although the most economical one, fails to unify the gauge coupling constants. Moreover, subsequent breaking of the Standard Model down to $SU(3) \\times U(1)_\\mathrm{em}$ with a $5$-dimensional representation fails to simultaneously provide viable masses for the down-type quarks and the charged leptons. We show that the substitution of the $24$-dimensional representation with a $75$-dimensional representation fixes the gauge coupling unification issue outrightly. We furthermore pin down, by computing the full mass spectrum of the multiplets in $75$-dimensional representation, the range of the unification scale $m_{\\rm GUT}$ to be $10^{15}\\,\\text{GeV} \\lesssim m_{\\rm GUT} \\lesssim 10^{16}\\,\\text{GeV}$. This unification window is partially excluded by Super-Kamiokande data and will be experimentally accessible at Hyper-Kamiokande. The second issue with the Georgi-Glashow model can be addressed, for example, with vectorlike fermions. The $24$-dimensional scenario admits three different types of vectorlike fermions that can properly account for the mismatch between the down-type quark and the charged lepton masses. The $75$-dimensional scenario, on the other hand, offers enhanced predictivity by allowing only a unique vectorlike addition of $10_F + \\overline{10}_F$ that restores realistic charged fermion masses and modestly pushes the upper limit on the unification scale to $m_{\\rm GUT} \\lesssim 3\\times10^{16}\\,\\text{GeV}$. The proposed framework with $75$-dimensional scalar representation can thus serve as a phenomenologically viable alternative to the standard Georgi-Glashow symmetry breaking paradigm.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.13376",
  "author_total": 3,
  "authors": [
    {
      "name": "Ilja Doršner"
    },
    {
      "name": "Mijo Matković"
    },
    {
      "name": "Shaikh Saad"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5n8b1j2wxxqqr.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.13376",
  "fulltext_url": null,
  "id": "5n8b1j2wxxqqr",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.13376",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2609.13376",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-11",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5n8b1j2wxxqqr.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:25Z",
      "native_id": "2609.13376",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.13376"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Predictive Non-Minimal SU(5) GUT",
  "title_text": "Predictive Non-Minimal SU(5) GUT",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:25Z",
  "url": "https://research.draconitic.com/paper/5n8b1j2wxxqqr",
  "venue": "arXiv",
  "versions": []
}