{
  "abstract": "The pronounced maximum (\"horn\") in the $K^+/π^+$ excitation function observed in central Pb+Pb collisions is well established feature of collision-energy dependence, but its dependence on system size remains poorly understood. We confront hadronic (SMASH) and partonic (PHSD) transport, Glauber core-corona, canonical-ensemble suppression, and the two-phase statistical model of the early stage (SMES) with $K^+/π^+$ data spanning the complete NA61/SHINE system-size ladder (p+p, Be+Be, Ar+Sc, Xe+La) together with NA49 Pb+Pb and STAR Au+Au, quantifying every comparison by $χ^2$. No single framework describes the full range: core-corona is preferred for intermediate systems, SMES with canonical strangeness conservation for heavy systems, and none reproduces the small-system data. Neither transport model generates the horn, with or without partonic degrees of freedom. The data exhibit a step-like enhancement of $K^+/π^+$ between Be+Be and Ar+Sc, quantified within the core-corona framework by a step from $\\fcore \\approx 0.22$ (Be+Be) to $\\fcore \\approx 0.58$ (Ar+Sc). The strangeness saturation factor $\\gs$ rises in two distinct steps, separating geometric core formation from thermodynamic equilibration. The $(K^+/π^+)/(K^-/π^-)$ double ratio, which at fixed $\\sqrts$ cancels the system-independent $μ_B$ contribution, shows a step between light and heavy systems at a global significance of $3.7σ$, providing evidence for genuine strangeness enhancement beyond the pair-production baseline. Preliminary Xe+La data favor core-corona ($\\chindf = 5.8$) over SMASH ($\\chindf = 23.3$); finalized spectra will sharpen the CC/SMES discrimination at the $27\\%$ level.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.28189",
  "author_total": 2,
  "authors": [
    {
      "name": "Neeraj"
    },
    {
      "name": "Amal Sarkar"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/62f98nc5wym9h.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.28189",
  "fulltext_url": null,
  "id": "62f98nc5wym9h",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.28189",
  "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"
    ],
    [
      "arxiv",
      "nucl-th"
    ],
    [
      "openalex",
      "3106|High-Energy Particle Collisions Research"
    ]
  ],
  "openalex": "W7204745597",
  "pdf_url": "https://arxiv.org/pdf/2608.28189",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/62f98nc5wym9h.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "2608.28189",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.28189"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    },
    {
      "field": "physics",
      "origin": "arxiv:nucl-th",
      "subfield": "nuclear"
    }
  ],
  "title": "System-size dependence of strangeness production from p+p to Pb+Pb: quantitative tests of the $K^+/π^+$ horn",
  "title_text": "System-size dependence of strangeness production from p+p to Pb+Pb: quantitative tests of the K^+/π^+ horn",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/62f98nc5wym9h",
  "venue": "arXiv",
  "versions": []
}