Master Thesis Open Access

Search for $B^+\to K^{*+}\tau^\pm \ell^\mp$ with hadronic tagging at the Belle II experiment

Fuchs, Lara


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    "description": "<p>Several observables in the flavor sector, including the charged current ratio <span class=\"math-tex\">\\(\\mathcal{R}(D^{(*)})\\)</span>&nbsp;and the evidence for neutral current <span class=\"math-tex\">\\(B^+\\to K^+\\nu\\bar\\nu\\)</span>&nbsp;have been hinting at deviation from the Standard Model.<br>\nMany proposed extensions predict enhanced rates for lepton flavor violating transitions such as <span class=\"math-tex\">\\(b \\to s \\tau\\ell\\)</span>,&nbsp;as there is no fundamental symmetry&nbsp;protecting lepton flavor conservation.&nbsp;</p>\n\n<p>This thesis provides first estimates of the upper limits on the branching fractions for <span class=\"math-tex\">\\(B^+\\to K^{*+}\\tau^\\pm \\ell^\\mp\\)</span>&nbsp;decay modes, using simulated samples corresponding to a dataset of <span class=\"math-tex\">\\(365\\,\\mathrm{fb}^{-1}\\)</span>&nbsp;collected at the<span class=\"math-tex\">\\(\\Upsilon (4\\mathrm{S})\\)</span>&nbsp;resonance by the Belle II experiment. The accompanying&nbsp;<span class=\"math-tex\">\\(B\\)</span>&nbsp;meson is reconstructed exclusively via hadronic decay modes, enabling&nbsp;signal extraction via a fit to the reconstructed&nbsp;invariant mass of the <span class=\"math-tex\">\\(\\tau\\)</span>&nbsp;lepton.</p>", 
    "publication_date": "2025-09-30", 
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      "subtype": "master-thesis", 
      "title": "Master Thesis", 
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      "report_number": "ETP-KA/2025-16", 
      "supervisors": [
        {
          "name": "Ferber, Torben"
        }, 
        {
          "name": "Klute, Markus"
        }, 
        {
          "name": "Goldenzweig, Pablo"
        }, 
        {
          "name": "van Tonder, Raynette"
        }
      ]
    }, 
    "title": "Search for $B^+\\to K^{*+}\\tau^\\pm \\ell^\\mp$ with hadronic tagging at the Belle II experiment"
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    166
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