{
  "abstract": "The thickness of the neutron skin ($Δr_{np}$) in $^{48}$Ca remains uncertain. CREX and ab initio calculations point to a thin skin, while many energy density functionals prefer larger values. Relativistic heavy-ion collisions can probe the skin through its geometric imprint on the quark-gluon plasma, but a thicker skin also changes the overall nuclear size, so the two effects are hard to separate. We resolve this by systematically comparing $^{48}$Ca+$^{48}$Ca and $^{48}$Ti+$^{48}$Ti collisions at $\\sqrt{s_{NN}}=5.02$ TeV using the AMPT model with string melting. For $^{48}$Ca, we take a zero-skin baseline and skins at the CREX lower and upper bounds. As size references, we add $^{48}$Ti and a skin-free $^{48}$Ca with the same density parameters as $^{48}$Ti, which separates size from skin effects. The sensitivity to the $^{48}$Ti radius is tested using two choices for its Woods-Saxon radius, one of which reproduces the experimental rms radius. We find that the neutron skin is a purely geometric perturbation; the medium's transport response coefficients are unchanged, first-moment observables exhibit only modest sensitivity to $Δr_{np}$, while second-moment observables respond much more strongly. The final-state covariance between flow and mean transverse momentum fluctuations, with its normalized correlation, is the most promising measurable probe. The radius-matched $^{48}$Ca follows $^{48}$Ti closely, and the position of $^{48}$Ti relative to the skin configurations depends on its radius. These collisions, analyzed with second-moment and shape-size correlators, offer a promising independent constraint on the $^{48}$Ca neutron skin at the LHC.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.38424",
  "author_total": 1,
  "authors": [
    {
      "name": "Abhisek Saha"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9skc53zbm0wka.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.38424",
  "fulltext_url": null,
  "id": "9skc53zbm0wka",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.38424",
  "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",
      "hep-ph"
    ],
    [
      "arxiv",
      "nucl-th"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2610.38424",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9skc53zbm0wka.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:36:23Z",
      "native_id": "2610.38424",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.38424"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    },
    {
      "field": "physics",
      "origin": "arxiv:nucl-th",
      "subfield": "nuclear"
    }
  ],
  "title": "Disentangling the neutron skin of $^{48}$Ca from nuclear radius effects through $^{48}$Ca+$^{48}$Ca and $^{48}$Ti+$^{48}$Ti flow observables",
  "title_text": "Disentangling the neutron skin of ^48Ca from nuclear radius effects through ^48Ca+^48Ca and ^48Ti+^48Ti flow observables",
  "type": "preprint",
  "updated_at": "2026-11-01T12:20:44Z",
  "url": "https://research.draconitic.com/paper/9skc53zbm0wka",
  "venue": "arXiv",
  "versions": []
}