Investigations of a conformal tracking algorithm with SiD at the ILC

  • Pieter J Keenan

Student thesis: Master's ThesisMaster of Science by Research (MScR)


The International Linear Collider (ILC) is a proposed electron-positron collider that would serve as a Higgs boson factory. Silicon Detector (SiD) is one of the general purpose experiments designed to study the full range of Higgs properties at the ILC. Successful charged particle tracking at SiD is required to achieve the ILC physics goals. This depends on the combined performance of the tracking detectors and the track reconstruction algorithm. The performance of a reconstruction algorithm, developed for another linear collider, that combines a conformal mapping approach with a cellular automaton into a conformal mapping algorithm is investigated in this thesis.

Conformal algorithm track finding is nearly fully efficient, with a low fake rate, for isolated muons produced at the interaction point that traverse the central region of the detector. For such particles with transverse momentum greater than 30 GeV, the reconstructed track transverse momentum resolution meets the ILC physics requirements. The step in the default algorithm that deals with tracks that originate away from the interaction point was causing reconstruction to fail with high angle low momentum particles. A modified version of the conformal tracking algorithm without the displaced track building step lead to reduced tracking efficiency for particles displaced in the (x, y) plane. The performance of the modified algorithm was worse than anticipated for simulated e+e-→ffH physics events. Despite this, the conformal tracking method shows potential to meet the SiD track reconstruction requirements. Optimisation of the algorithm for the SiD geometry is required to translate the isolated muon performance across to the more complex physics events.
Date of Award23 Jan 2024
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorJoel Goldstein (Supervisor)


  • Tracking algorithm
  • Higgs boson
  • Collider
  • Conformal mapping

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