{
  "abstract": "Spin-orbit coupling makes the mean position of a spinning particle transform anomalously under a Lorentz boost, with an additional shift known as a side jump. In this work, we develop a trace method to derive an exact but compact transformation kernel for the probability center of a general three-dimensional Dirac wave packet under an arbitrary finite Lorentz boost. The expression includes the physics of finite momentum width, spin-momentum correlations, and coherent phase structure without a semi-classical expansion. We identify texture-dependent side jumps even at fixed initial mean momentum, spin, and orbital angular momentum, as well as a non-monotonic mass dependence for Gaussian packets at fixed momentum width. The explicit kernels further resolve the spin and orbital angular-momentum contributions for massive and massless fermions, providing a kinematic basis for covariant particle-based spin transport that retains wave-packet information.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.36416",
  "author_total": 2,
  "authors": [
    {
      "name": "Jin-Rui Wu"
    },
    {
      "name": "Shuai Y. F. Liu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3vxqf31nhtmfm.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.36416",
  "fulltext_url": null,
  "id": "3vxqf31nhtmfm",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.36416",
  "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-th"
    ],
    [
      "arxiv",
      "nucl-th"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "3107|Quantum and electron transport phenomena"
    ]
  ],
  "openalex": "W7224131918",
  "pdf_url": "https://arxiv.org/pdf/2610.36416",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3vxqf31nhtmfm.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:50Z",
      "native_id": "2610.36416",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.36416"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-th",
      "subfield": "high-energy"
    },
    {
      "field": "physics",
      "origin": "arxiv:nucl-th",
      "subfield": "nuclear"
    },
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Side jump and anomalous Lorentz transformation of a coherent Dirac wave packet",
  "title_text": "Side jump and anomalous Lorentz transformation of a coherent Dirac wave packet",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:50Z",
  "url": "https://research.draconitic.com/paper/3vxqf31nhtmfm",
  "venue": "arXiv",
  "versions": []
}