Master Thesis Open Access
Dorwarth, Philipp Benjamin
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"@type": "ScholarlyArticle",
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"@type": "Person",
"affiliation": "KIT/ETP",
"name": "Dorwarth, Philipp Benjamin"
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"datePublished": "2023-05-16",
"description": "<p>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. The thesis examines input features for real-time pattern recognition algorithms, systematic graph-building in the Central Drift Chamber (CDC), which serves as the primary tracking detector, and the use of the Interaction Network (IN) for edge classification and background clean-up.</p>\n\n<p>The study finds that Analog-to-Digital Converter (ADC) count and Time-to-Digital Converter (TDC) count, representing deposited energy and associated timing information in a CDC cell, provide orthogonal discrimination power, making them both valuable for distinguishing signal from background.</p>\n\n<p>Different patterns for graph-building in the CDC are analyzed to find graphs that effectively encapsulate crucial information about signal particle tracks of a simulated Inelastic Dark Matter with a Dark Higgs model. Metrics are introduced to aid in balancing between capturing essential edges connecting signal hits and excluding those associated with background.</p>\n\n<p>The graphs are evaluated, employing the IN as a classifier for graph edges. This process allows for the identification of signal hits and the execution of a background clean-up. The clean-up task yields a promising result, correctly identifying up to (80.6 ± 0.4) % of signal hits in the CDC while maintaining a purity of (67.4 ± 0.4) % in the hit selection. An initial analysis towards a real-time implementation is also conducted, aligning the input feature resolution with the anticipated resolutions at the Level 1 Trigger (L1 Trigger) stage.</p>\n\n<p>This thesis provides encouraging evidence that a GNN-based pipeline offers a viable solution to the challenges posed.</p>",
"headline": "Graph-Building and Input Feature Analysis for Edge Classification in the Central Drift Chamber at Belle II",
"image": "https://publish.etp.kit.edu/static/img/logos/zenodo-gradient-round.svg",
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"alternateName": "eng",
"name": "English"
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"keywords": [
"Belle II",
"Graph Neural Network",
"Deep Learning",
"Graph-Building",
"Pattern Recognition",
"Central Drift Chamber",
"Displaced Vertices"
],
"name": "Graph-Building and Input Feature Analysis for Edge Classification in the Central Drift Chamber at Belle II",
"url": "https://publish.etp.kit.edu/record/22197"
}