{
  "abstract": "The transverse helicity fractions of $W$ bosons are measured as a function of the $W$ boson rapidity, $y_{W}$, in the range $0 \\leq y_{W} \\leq 5$ using $W\\toμν_μ$ decays in $pp$ collisions at $\\sqrt{s}$ = 13 TeV recorded by the LHCb experiment and corresponding to an integrated luminosity of $5.1$ fb$^{-1}$. The fractions are extracted from a template fit to the muon transverse momentum and pseudorapidity. The results show a strong rapidity dependence and agree with next-to-leading-order Standard Model predictions, providing the first determination of the transverse helicity fractions of $W$ bosons in the forward region.",
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  "arxiv": "2609.22555",
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    {
      "name": "R Aaij"
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      "name": "M Abdelfatah"
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    },
    {
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    {
      "name": "T Ackernley"
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    {
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      "name": "M Adinolfi"
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      "name": "P Adlarson"
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      "name": "C.A Aidala"
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      "name": "S Akar"
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      "name": "S. Arguedas Cuendis"
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      "name": "L Arnone"
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      "name": "M Artuso"
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    {
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    {
      "name": "S Bachmann"
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    {
      "name": "J.J Back"
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    {
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      "name": "L Balzani"
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    {
      "name": "H Bao"
    },
    {
      "name": "J. Baptista de Souza Leite"
    },
    {
      "name": "C Barbero Pretel"
    },
    {
      "name": "I.R Barbosa"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3k336az6dmeby.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.22555",
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  "pdf_url": "https://arxiv.org/pdf/2609.22555",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3k336az6dmeby.ris",
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      "first_seen": "2026-10-30T12:17:40Z",
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      "url": "https://arxiv.org/abs/2609.22555"
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  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
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  "title": "First measurement of the forward rapidity dependence of $W$ boson transverse helicity fractions",
  "title_text": "First measurement of the forward rapidity dependence of W boson transverse helicity fractions",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:56Z",
  "url": "https://research.draconitic.com/paper/3k336az6dmeby",
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