2.
| Study of sPlot Background Subtraction for Particle Identification Efficiency Determination at Belle II
/ Lars von der Werth ; Stefan Wallner
[BELLE2-UTHESIS-2024-003]
Presented on 29 10 2024 BSc
2024
Max Planck Institut for Physics
/ Garching
Particle identification is a central experimental challenge in the precise measurement of Standard Model parameters and in the search for new physics beyond the standard model at the Belle II experiment. [...]
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3.
| Tests of lepton universality in the rates of inclusive semileptonic B-meson decays at Belle II
/ Henrik Junkerkalefeld ; Jochen Dingfelder ; Peter Lewis ; Florian Bernlochner
[BELLE2-PTHESIS-2024-017]
Presented on 28 06 2024 PhD
2024
Physikalisches Institut
/ Bonn
This thesis presents two precision tests of lepton universality: the first measurement of the ratio of light-lepton branching fractions of inclusive semileptonic $B$-meson decays, $R(X_{e/mu}) = \mathcal{B}(B \to Xe\nu) / \mathcal{B}(B \to X\mu\nu)$, and the first successful measurement of inclusive $B \to X\tau\nu$ decays, measured in a ratio relative to $B \to X\ell\nu$ decays ($\ell = e, \mu$), $R(X_{\tau/\ell}) = \mathcal{B}(B \to X\tau\nu) / \mathcal{B}(B \to X\ell\nu)$. [...]
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4.
| Search for B+ -> K+ nu nubar at Belle II using Graph Neural Networks
/ Merna Abumusabh ; Giulio DUJANY ; Jacopo CERASOLI
[BELLE2-MTHESIS-2024-021]
Presented on 19 06 2024 MSc
2024
IPHC
/ Strasbourg
This work presents the search for the decay of a charged B-meson into a charged kaon and a pair of neutrinos via graph-tagged analysis, which is an approach based on graph neural network, in Belle~II, which is operating at the asymmetric electron-positron collider SuperKEKB located at KEK, Tsukuba, Japan. [...]
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5.
| Implementing the TabNet Deep Learning Algorithm for Selecting τ−→π−π−π+ντ Events from Belle II Data
/ Yannik Fausch
[BELLE2-UTHESIS-2024-002]
Presented on 29 10 2024 BSc
2024
Max Planck Institut for Physics
/ Garching
This thesis aims to compare TabNet, a Deep Learning (DL) algorithm for classi- fication of tabular data, to the established Boosted Decision Tree (BDT) used for event selection of the τ − → π−π−π+ντ decay. [...]
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6.
| Measurement of the Branching Fraction of Charmless Semileptonic B Meson Decays and the Quark-Mixing Matrix Element Vub with the Belle II Experiment
/ Andrea Fodor ; Andreas Warburton
[BELLE2-PTHESIS-2024-016]
Presented on 25 05 2024 PhD
2024
McGill University
/ Montreal
This thesis presents the first inclusive untagged analysis of $B \to X_u \ell \nu$ decays using data from the Belle II experiment. [...]
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7.
| Measurement of |Vus| using hadronic τ decays at Belle II
/ Géraldine Räuber ; Christoph Schwanda ; Gianluca Inguglia
[BELLE2-PTHESIS-2024-015]
Presented on 14 06 2024 PhD
2024
HEPHY
/ Vienna
This thesis presents a precise measurement of the CKM matrix element Vus using data collected at the Belle II experiment situated at the SuperKEKB electron- positron collider in Tsukuba, Japan. [...]
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8.
| Improving the Belle II Neural Track Trigger with Deep Neural Networks
/ Timo Forsthofer ; Prof. Christian Kiesling
[BELLE2-MTHESIS-2024-020]
Presented on 30 06 2024 MSc
2024
Max-Planck-Intitute for Physics
/ Garching
In order to provide accurate measurements of Standard Model parameters and search for new physics at the precision frontier [1], the Belle II experiments aims to reach an instantaneous luminosity of 6 × 1035 cm−2s−1 [2]. [...]
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9.
| Test of light-lepton universality in tau decays with data from the Belle II experiment
/ Paul Feichtinger ; Gianluca Inguglia ; Christoph Schwanda
[BELLE2-PTHESIS-2024-014]
Presented on 14 06 2024 PhD
2024
Atominstitut TU Wien / HEPHY
/ Vienna
This thesis investigates light-lepton universality with electron-positron collision data from the Belle~II experiment at the SuperKEKB accelerator in Tsukuba, Japan. [...]
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10.
| Graph-Building and Input Feature Analysis for Edge Classification in the Central Drift Chamber at Belle II
/ Philipp Dorwarth ; Torben Ferber
[BELLE2-MTHESIS-2024-019]
Presented on 16 05 2024 MSc
2024
Karlsruhe Institute of Technology
/ Karlsruhe
This thesis investigates components of a Graph Neural Network (GNN)-based pipeline addressing challenges of current tracking algorithms at the Belle II experiment, such as highly displaced vertices and escalating beam backgrounds. [...]
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11.
| Upgrade of Belle II's Neural Network Trigger by Track Finding in Three-Dimensional Hough Space
/ Simon Hiesl ; Prof. Dr. Christian Kiesling
[BELLE2-MTHESIS-2024-018]
Presented on 12 04 2024 MSc
2024
Max-Planck-Institute for Physics
/ Munich
The target luminosity of the Belle II experiment, located at the SuperKEKB electron-positron collider in Tsukuba, Japan, is 6x10^{35} cm^{-2}s^{-1}. [...]
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