Initial Tests Of The Pion Beta Decay Detector - Contents

• 1 Introduction
  • 1.1 The pion.
  • 1.2 Experimental motivation
  • 1.3 Neutron decay
    • 1.3.1 Nuclear beta decay
  • 1.4 Previous p -> e n ( g ) measurements
    • 1.4.1 Czapek, et al. (1993)
    • 1.4.2 Britton, et al. (1992,1994)
  • 1.5 Previous p + -> p 0 e+ n measurements
    • 1.5.1 Depommier et al. (1968)
    • 1.5.2 McFarlane et al. (1985)
  • 1.6 Summary
• 2 Theoretical Background
  • 2.1 The weak force
  • 2.2 Conserved vector current hypothesis
    • 2.2.1 Theoretical motivation
    • 2.2.2 Isospin formulation
  • 2.3 Calculation of branching ratios
    • 2.3.1 Calculation of the [lambda]( p + -> p 0 e+ n ) / [lambda]([pi]+ -> µ+ n ) branching ratio
    • 2.3.2 Calculation of [lambda]( p + -> e+ n ) / [lambda]( p + -> µ+ n ) branching ratio
    • 2.3.3 Radiative corrections
• 3 Experimental Technique
  • 3.1 The Paul Scherrer Institute accelerator
    • 3.1.1 Accelerator components
      • 3.1.1.1 Pre-Injector
      • 3.1.1.2 Injector II
      • 3.1.1.3 Ring accelerator
  • 3.2 The Paul Scherrer Institute beam lines
    • 3.2.1 Production targets
    • 3.2.2 The p E1 beam line
  • 3.3 Experimental Apparatus
    • 3.3.1 The pion beta decay project detector
    • 3.3.2 Targets
    • 3.3.3 Multi-wire proportional chambers
    • 3.3.4 Detector components used in the 1996 and 1997 beam times
      • 3.3.4.1 Platform
      • 3.3.4.2 Beam counter and collimator
      • 3.3.4.3 Wire chambers
      • 3.3.4.4 Thermal house
      • 3.3.4.5 Target and degrader
      • 3.3.4.6 Plastic veto array
      • 3.3.4.7 CsI crystals
      • 3.3.4.8 Data acquisition system
    • 3.3.5 Trigger electronics
      • 3.3.5.1 Overview
      • 3.3.5.2 Analog leg
      • 3.3.5.3 Trigger leg
      • 3.3.5.4 Beam line detectors
    • 3.3.6 Data acquisition software
      • 3.3.6.1 Trigger frontend computer
      • 3.3.6.2 Slow controls frontend computer
      • 3.3.6.3 Backend computer
• 4 Plastic Veto Array
  • 4.1 Geometry
  • 4.2 Material properties
    • 4.2.1 Scintillator
    • 4.2.2 Photomultiplier tubes
  • 4.3 Preparation of the staves
    • 4.3.1 Gluing
    • 4.3.2 Polishing
    • 4.3.3 Annealing
    • 4.3.4 Wrapping
  • 4.4 Tomography
    • 4.4.1 Apparatus
    • 4.4.2 Effective attenuation length
    • 4.4.3 Signal velocity
  • 4.5 Summary
• 5 Data Reduction and Analysis
  • 5.1 Analysis software
  • 5.2 Data reduction
    • 5.2.1 Pedestal subtraction
    • 5.2.2 Noise reduction
  • 5.3 Energy and timing spectra
  • 5.4 Extraction of the branching ratio R
    • 5.4.1 Determination of the "raw" ratio Rraw
    • 5.4.2 Determination of the correction Rts
    • 5.4.3 Determination of the correction factor Rlh
    • 5.4.4 Determination of the gate timing correction f-1
    • 5.4.5 Determination of the low energy tail correction
    • 5.4.6 Evaluation of the branching ratio
• 6 Conclusion