Contents

• Contents
• List of Figures
• List of Tables
• The Large Hadron Collider
• Higgs physics at the LHC
  • The standard model Higgs
    • Spontaneous symmetry breaking
    • The Higgs mechanism
  • Higgs Production
    • Gluon fusion
    • Vector boson fusion
    • Associate production
  • Higgs decays
    • Vector boson decay
    • Fermionic decays
    • Two photon decay
    • Two gluon decay
  • Experimental results on Higgs searches
  • A theoretical limit on the Higgs mass
    • The triviality bound
    • The width of the Higgs
    • WW $\rightarrow$ WW scattering
    • A value for the maximal Higgs mass
  • Higgs searches at the LHC
    • An intermediate mass Higgs (m_Z < m_H < 2m_Z)
    • A heavy Higgs ( 2m_Z < m_H < 650 GeV)
    • A very heavy Higgs ( m_H > 650 GeV)
  • No Higgs particle at all
• Transition radiation detectors
  • Transition radiation from a single boundary
  • Radiators with many layers
  • N foils placed with regular spacing
  • The detection gas
    • Absorption of transition radiation photons
    • Ionisation from charged particles
  • Considerations for design
  • Previous transition radiation detectors
• Design of the ATLAS detector
  • Magnet system
  • The muon system
  • The calorimeter
    • The liquid argon calorimeter
    • The tile calorimeter
  • The Inner Detector
    • The silicon detectors
    • The Transition Radiation Tracker
  • Trigger and computing aspects
• Testbeam analysis
  • The Transition Radiation Tracker sector prototype
  • Front-end electronics and readout
    • System overview
    • Transition Radiation Detector Analog (TRDA) chip
    • Transition Radiation Detector Service (TRDS) chip
    • Drift-Time Measuring ReadOut Chip (DTMROC)
    • Front-end boards
    • Back-end electronics
  • Testbeam setup
  • Track reconstruction and alignment
  • Beam purity
  • The simulation of transition radiation detectors
    • Simulation of the transition radiation spectrum
    • Energy absorption in a straw
    • Electronics response
  • The Monte Carlo model of the testbeam
    • The modules in the testbeam simulation
      • The silicon beam telescope
      • Beam chambers
      • Counters
      • TRT prototype
      • Material distribution
    • Calibrating the Monte Carlo model
  • Electron identification
    • Effect of the detector length
    • Effect of the magnetic field
    • Effect of changing the straw density
    • Effect of the gas parameters
  • Summary of performance
• ATLAS Monte Carlo simulations
  • Simulation
  • Pattern recognition in the Inner Detector
    • Pattern recognition methods
    • Fake tracks in the TRT
  • Conversion identification
    • Pattern recognition in the TRT
    • The conversion algorithm
• The Higgs to two photon decay channel
  • Mass resolution of signal
  • Methods for primary vertex determination
  • Conversions
  • Global track reconstruction
    • The algorithm
    • Results
    • Uncertainties in the underlying physics
  • Calibration of cluster energies
  • Influence on Higgs mass resolution and significance
  • Irreducible two photon background
  • Reducible QCD-jet background
    • Single $\pi^{0}_{}$ rejection
    • Final estimate of reducible background
  • Signal significance
  • Summary of the H $\rightarrow$ $\gamma$$\gamma$ decay channel
• Identification of a heavy Higgs
  • Reducible backgrounds
  • Irreducible vector boson background
    • V_LV_L background
    • V_TV_L/T background
    • Continuum VV background
  • Simulated events
  • The four jet channels
    • Vector boson reconstruction
    • Tag jets
    • Significance of signal
  • The H $\rightarrow$ W ⁺W ^- $\rightarrow$ l$\nu$jj channel
    • Vector boson reconstruction
    • Tag jets
    • Jet and track veto
    • Significance of signal
  • The H $\rightarrow$ ZZ $\rightarrow$ l ⁺l ^-$\nu$$\bar{\nu}$ channel
  • The H $\rightarrow$ ZZ $\rightarrow$ l ⁺l ^-jj channel
  • Uncertainties in the size of signal and background
    • Structure functions
    • jW cross section
    • VV $\rightarrow$ VV cross section
    • Tag jets
    • Colour flow in PYTHIA
  • Final estimate of a heavy Higgs signal
• Summary
• Acknowledgements
• References