I= MEASUREMENT OF THE CROSS SECTION FOR E+E-> HADRONS AT Z0 RESONANCE WITH THE L3 DETECTOR
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Title of Thesis
MEASUREMENT OF THE CROSS SECTION FOR E+E-> HADRONS AT Z0 RESONANCE WITH THE L3 DETECTOR

Author(s)
Rukhsana Malik
Institute/University/Department Details
Department of Physics/ Quaid-i-Azam University, Islamabad
Session
1996
Subject
Physics
Number of Pages
112
Keywords (Extracted from title, table of contents and abstract of thesis)
hadrons, l3 detector, lep, z0, large electron positron, l3 trigger system, hadronic cross section

Abstract
A precise measurement of the cross section of the process e+ e- †’ hadrons from the data produced by LEP and detected by L3 during 1991 is done. The total luminosity of 12.634 pb-1, corresponding to approximately 301,600 e+ e- †’ hadrons events, was recorded around the Z0 resonance. The Z0 parameters determined from a model independent fit to the cross section are:

Mz = 91.189 ± 0.006 ± 0.006 (LEP) GeV

Tz = 2.504 ± 0.010 GeV

Thad = 1.739 ± 0.018 Ge V

By interpreting the data in terms of the Standard Model and assuming lepton universality the number of light neutrino families is determined :

Nv = 3.07± 0.08 ± 0.080

In the framework of the Standard Model, the top quark mass is estimated to be :

mt= 185+34-42 ±15(Higgs) GeV

Download Full Thesis
1496.11 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents 0
69.67 KB
2 1 Introduction 1
37.04 KB
  1.1 Introduction 2
3 2 Theory 4
223.31 KB
  2.1 Introduction 5
  2.2 Theoretical Motivation for the Z0 Vector Boson 5
  2.3 Theoretical Predictions for the Z0 Cross Section 13
4 3 Experimental Apparatus 25
399.23 KB
  3.1 The Large Electron Positron Collider (LEP ) 26
  3.2 The L3 Detector 27
  3.3 The L3 Trigger System 41
5 4 Event Reconstruction And Simulation 45
173.49 KB
  4.1 The L3 Reconstruction Program REL3 46
  4.2 The Simulation Program SIL3 51
  4.3 Monte Carlo Programs 53
6 5 Data Analysis 55
491.92 KB
  5.1 Measurement of Hadronic Cross Section 56
  5.2 The Hadronic Cross Section 76
  5.3 Systematic Uncertainty 78
7 6 Determination of Electroweak Parameters 91
237.9 KB
  6.1 The Electroweak Parameters 92
  6.2 Conclusions 98
  6.3 Summary of Results 101