{
  "abstract": "We investigate the UV viability of strongly first-order electroweak phase transitions (SFOEWPTs) in the Type-I two-Higgs-doublet model (2HDM), considering both the Normal and Inverted Scenarios (NS and IS). For each scenario, we scan $5\\times10^6$ physical parameter points and determine the cutoff scale $Λ_{\\rm c}$ through a two-loop renormalization-group analysis, where $Λ_{\\rm c}$ is set by the first violation of perturbativity, tree-level unitarity, or vacuum stability. For one-step transitions, the SFOEWPT strength and high-scale UV validity exhibit a pronounced tension: the maximal transition strength $ξ_p$ decreases with increasing $Λ_{\\rm c}$. Requiring $Λ_{\\rm c}>10~\\text{TeV}$ limits the transition strength to $ξ_p\\lesssim2.7$ in the NS and $ξ_p\\lesssim1.8$ in the IS, while requiring $ξ_p>1$ restricts the cutoff scale to $Λ_{\\rm c}\\lesssim O(10^6)~\\text{GeV}$ in both scenarios. Multistep transitions exhibit qualitatively different behavior. Two-step SFOEWPTs, found in appreciable numbers only in the IS, can remain theoretically consistent up to $Λ_{\\rm c}\\sim O(10^{15})~\\text{GeV}$ while reaching $ξ_p\\simeq7$, without exhibiting the pronounced $ξ_p$-$Λ_{\\rm c}$ anticorrelation characteristic of one-step transitions. Imposing UV validity also sharpens the phenomenologically viable parameter space. In particular, increasing the minimum allowed cutoff scale for two-step SFOEWPTs in the IS favors a light scalar spectrum and moderate $\\tanβ$, providing a promising target for current and future collider searches.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.09444",
  "author_total": 4,
  "authors": [
    {
      "name": "Jin-Hwan Cho"
    },
    {
      "name": "Dongjoo Kim"
    },
    {
      "name": "Jinheung Kim"
    },
    {
      "name": "Jeonghyeon Song"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dyb9etpk3r4sp.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.09444",
  "fulltext_url": null,
  "id": "dyb9etpk3r4sp",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.09444",
  "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|Particle physics theoretical and experimental studies"
    ]
  ],
  "openalex": "W7212193305",
  "pdf_url": "https://arxiv.org/pdf/2609.09444",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/dyb9etpk3r4sp.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:12Z",
      "native_id": "2609.09444",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.09444"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Cutoff Scales in the Type-I 2HDM with Strongly First-Order Electroweak Phase Transitions: One-Step versus Multistep",
  "title_text": "Cutoff Scales in the Type-I 2HDM with Strongly First-Order Electroweak Phase Transitions: One-Step versus Multistep",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:12Z",
  "url": "https://research.draconitic.com/paper/dyb9etpk3r4sp",
  "venue": "arXiv",
  "versions": []
}