{
  "abstract": "We evaluate the transport coefficients, namely the shear viscosity $η$ and the spatial diffusion coefficient of heavy quarks $D_s$, within a Quasi-Particle Model (QPM). In particular, for the first time this has been done by exploiting novel lQCD data at $N_f=3+1$. In such a framework, in which the gluons are massive, the interactions among quarks and gluons have been evaluated via the scattering matrices evaluated from tree level Feynman diagrams. As far as the evaluation of $D_s$ is concerned, the Fokker-Planck approximation for the relativistic Boltzmann equation has been employed for the diffusion of both charm and bottom quarks in either a $N_f=3$ and a $N_f=3+1$ bulk. We have developed a dual-component Chapman-Enskog formalism for the ratio $η/s$ (being $s$ the entropy density) of a mixture of quarks and gluons. The temperature dependence of the shear viscosity is then compared to the results from a Green-Kubo approach, based on the numerical resolution of the relativistic Boltzmann equation with a stochastic implementation of the collision integral. Finally, using the above results, we compare the strong and weak coupling regimes for the ratio $(2πT D_s)/(4πη/s)$.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.08521",
  "author_total": 1,
  "authors": [
    {
      "name": "Gabriele Parisi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fsamw8e0savf5.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.08521",
  "fulltext_url": null,
  "id": "fsamw8e0savf5",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.08521",
  "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|High-Energy Particle Collisions Research"
    ]
  ],
  "openalex": "W7212016612",
  "pdf_url": "https://arxiv.org/pdf/2609.08521",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fsamw8e0savf5.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:52Z",
      "native_id": "2609.08521",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.08521"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Hot QCD: transport coefficients in strong and weak coupling regimes",
  "title_text": "Hot QCD: transport coefficients in strong and weak coupling regimes",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:52Z",
  "url": "https://research.draconitic.com/paper/fsamw8e0savf5",
  "venue": "arXiv",
  "versions": []
}