{
  "abstract": "In this paper we revisit, from a different perspective, a long-standing question: ``Is the systematic deficit observed in all branching ratios mediated by a $b\\to s μμ$ transition due to New Physics, or to a hypothetical constant unknown universal hadronic contribution that mimics New Physics?'' The key observation that allows us to distinguish between these two possibilities is that non-perturbative contributions associated with $c\\bar c$ loops affect inclusive $B\\to X_s \\ell\\ell$ and exclusive $B\\to K^{(*)}\\ell\\ell$ modes differently. In inclusive decays, factorizable contributions are exactly determined from data on $e^+e^-\\to \\mathrm{hadrons}$, while non-factorizable corrections are described by resolved-photon contributions at low $q^2$ and by local power corrections at high $q^2$. In exclusive decays, by contrast, hypothetical charming-penguin effects, beyond those already included in current uncertainty estimates, could appear, in a worst-case scenario, as a constant, universal contribution that it seems, in principle, indistinguishable from genuine New Physics. We identify two observables, constructed from ratios of exclusive to inclusive modes, that can discriminate between a New Physics contribution and a constant hadronic contribution. Moreover, these ratios can be measured directly by LHCb, as they do not require any normalisation to $J/ψK^{(*)}$ branching fractions from B factories. A preliminary evaluation of these observables with present data shows some preference for the New Physics interpretation. In a complementary test, a comparison between inclusive measurements and the corresponding sum of exclusive modes at high $q^2$ similarly disfavours an explanation based on a constant hadronic contribution. Finally, we provide projections for the new observables based on expected LHCb and Belle II measurements in the near future.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2605.06567",
  "author_total": 4,
  "authors": [
    {
      "name": "P. Alvarez-Cartelle"
    },
    {
      "name": "B. Capdevila"
    },
    {
      "name": "E. Lunghi"
    },
    {
      "name": "J. Matias"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/22b7npnhvw8pj.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2605.06567",
  "fulltext_url": null,
  "id": "22b7npnhvw8pj",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2605.06567",
  "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-ex"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3106|Particle physics theoretical and experimental studies"
    ]
  ],
  "openalex": "W7160663987",
  "pdf_url": "https://arxiv.org/pdf/2605.06567",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/22b7npnhvw8pj.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:12Z",
      "native_id": "2605.06567",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2605.06567"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Probing unknown nonperturbative effects in $b \\to s \\ell\\ell$ with inclusive and exclusive observables",
  "title_text": "Probing unknown nonperturbative effects in b → s ℓℓ with inclusive and exclusive observables",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:12Z",
  "url": "https://research.draconitic.com/paper/22b7npnhvw8pj",
  "venue": "arXiv",
  "versions": []
}