{
  "abstract": "Particle production from bubble collisions during First-Order Phase Transitions (FOPTs) has been studied as an efficient mechanism for baryogenesis and dark matter production, but existing semi-analytical treatments assume runaway bubbles with wall velocity $v_w\\to 1$. We generalize this treatment to arbitrary $v_w< 1$, relevant for scenarios such as electroweak baryogenesis and transitions with significant wall friction. We first extend the analytical trapping-equation approach to finite-thickness boosted kink profiles for both elastic and inelastic collisions, then go beyond this by numerically solving the full Klein-Gordon equation without assuming $SO(1,1)$ symmetry or thin walls, across a broad grid of $v_w$ and potential shapes. We find the analytical generalization underestimates the true efficiency factor by orders of magnitude away from $v_w\\to 1$, and provide new semi-analytic fit functions consisting of a power-law continuum plus a resonance peak, which reproduce the main spectral features of the numerical results across the parameter range studied. Applying these to a toy dark sector model, we show particle production is strongly suppressed as $v_w$ decreases from unity, enhanced for lighter produced particles, and that the relative contribution from the oscillatory peak differs from prior runaway-regime estimates. We also discuss limitations of the trapping equation and the off-shell effective-action truncation underlying this formalism.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.30106",
  "author_total": 4,
  "authors": [
    {
      "name": "Fayez Abu-Ajamieh"
    },
    {
      "name": "Amine Ahriche"
    },
    {
      "name": "Sagar Modak"
    },
    {
      "name": "Nobuchika Okada"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5yet24e2xrxwp.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.30106",
  "fulltext_url": null,
  "id": "5yet24e2xrxwp",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.30106",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.CO"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3106|Particle physics theoretical and experimental studies"
    ]
  ],
  "openalex": "W7223215922",
  "pdf_url": "https://arxiv.org/pdf/2610.30106",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-21",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5yet24e2xrxwp.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:19Z",
      "native_id": "2610.30106",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.30106"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "On Particle Production from Bubble Collisions in the Non-runaway Regime",
  "title_text": "On Particle Production from Bubble Collisions in the Non-runaway Regime",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:19Z",
  "url": "https://research.draconitic.com/paper/5yet24e2xrxwp",
  "venue": "arXiv",
  "versions": []
}