Table Of Contents

0 Abstract
1 Introduction
    1.1 Elementary Particles
    1.2 Fundamental Interactions
    1.3 Neutrino Counting
    1.4 Thesis Overview
2 Theoretical Background
    2.1 Theory of Neutrino Counting
    2.2 The Invisible Width Method
    2.3 The Single Photon Counting Method
        2.3.1 The Lowest Order Cross-Section
        2.3.2 Single Photon Spectra
3 Experimental Apparatus
    3.1 The LEP collider
    3.2 The OPAL Detector
        3.2.1 Beam Pipe and Magnet
        3.2.2 Central Tracking Systems
        3.2.3 The Barrel Time-of-Flight System
        3.2.4 Electromagnetic Presampler
        3.2.5 Electromagnetic Calorimeters
        3.2.6 Hadronic Calorimeters
        3.2.7 Muon Detectors
        3.2.8 Forward Detectors
    3.3 The Luminosity Measurement
4 The OPAL Data Environment
    4.1 The Data Acquisition Flow
    4.2 The Trigger
    4.3 The Single Photon Trigger
    4.4 Filter and Reconstruction
    4.5 Data Storage and Distribution
    4.6 Event Display
5 The OPAL Monte Carlo Environment
    5.1 Monte Carlo Generation
    5.2 Electroweak Effects in Monte Carlos
    5.3 Electroweak Monte Carlo Generators
        5.3.1 The NNG04 Monte Carlo
        5.3.2 The TEEGG Monte Carlo
        5.3.3 The RADCOR Monte Carlo
        5.3.4 The TWOGEN Monte Carlo
        5.3.5 The VERMAS Monte Carlo
        5.3.6 The KORALZ Monte Carlo
        5.3.7 The BABAMC Monte Carlo
    5.4 The OPAL Detector Simulation
6 The Single Photon Signal and Selection
    6.1 Single Photon Selection in the Barrel
        6.1.1 Event Quality and Acceptance Criteria
        6.1.2 The Cluster Size Criterion
        6.1.3 The Second Cluster Veto Criterion
        6.1.4 The Central Detector Veto Criterion
        6.1.5 The Forward Detector Veto Criterion
        6.1.6 The Presampler Match Criterion
        6.1.7 The Muon Chamber and HCAL Veto Criteria
        6.1.8 The Single Photon Events in the Barrel
    6.2 Single Photon Selection in the Endcap
        6.2.1 Study of the Endcap Single Photon Acceptance
        6.2.2 The Results of the Simulation Corrected Four-Vectors Study in the Endcap
7 Single Photon Energy Loss and Resolution
    7.1 Single Photon Energy Loss and Resolution
    7.2 The Single Electron Sample
    7.3 Single Electron Energy Loss and Resolution
8 Single Photon Efficiencies
    8.1 Trigger Efficiencies
    8.2 Single Photon Selection Efficiencies
    8.3 Veto Efficiencies
    8.4 The Overall Efficiency
9 Single Photon Backgrounds
    9.1 Simulation of Single Photon Backgrounds
    9.2 The Bhabha Background
    9.3 The Cosmic and Beam Related Background
    9.4 Total Backgrounds
10 Results and Conclusions
    10.1 Two Single Photon Samples
    10.2 Systematic Errors
    10.3 The 1991 Measurement of N_n and G_Z⁰^inv
    10.4 The Combined Measurement of N_n and G_Z⁰^inv
    10.5 Conclusions
A Gauge Theories
B The Standard Model
C Radiative Corrections

Edward G. Heflin. Š2001. All rights reserved.