Contents About the Authors Preface to the Second Edition Preface to the First Edition Chapter 1. Overview 1 References 7 Chapter 2. Symmetry and Conservation Law 9 2.1 Introduction 9 2.2 The Action, Equation of Motion and Conserved Quantities 10 2.3 Parity Transformation 14 2.3.1 Klein-Gordon field *(x) 15 2.3.2 Parity transformation of fermion field 16 2.3.3 Parity transformation of vector field 18 2.4 Charge Conjugation 19 2.4.1 Charge conjugation of scalar field 19 2.4.2 Charge conjugation of fermion field *(x) 19 2.4.3 Charge conjugation of vector field A*{x) 22 2.5 Application: Furry Theorem — A Particle of Spin 1 Cannot Decay to 27 22 2.5.1 Furry theorem 22 2.5.2 Particles of spin 1 cannot decay into two photons 23 2.6 Time Reversal 25 2.6.1 Time reversal of Klein-Gordon field *(x) 29 2.6.2 Time reversal of fermion field 29 2.6.3 Time reversal of electromagnetic field A* (x) 30 2.7 CPT Theorem 33 References 34 Chapter 3. The Classification and Properties of Particles: Lepton and Hadrons 37 3.1 Four Types of Interactions 37 3.2 Lepton and Lepton Number Conservation 40 3.2.1 Electron, muon and neutrino 40 3.2.2 * and its neutrino v* 43 3.2.3 Helicity of neutrinos 44 3.2.4 Lepton number conservation 46 3.3 Hadrons: Conservation of Baryon Numbers 47 3.3.1 π meson 48 3.3.2 Nucleon, antinucleon and baryon number conservation 52 3.3.3 Strange particles 53 3.3.4 Resonance 57 3.4 Scattering Cross Section, Particle Lifetime and Decay Width 63 3.4.1 Scattering cross section 63 3.4.2 Particle lifetime and decay width 67 3.5 Kinematics of Particle Decay 68 3.5.1 Two-body decay 68 3.5.2 Three-body decay, Dalitz diagram 69 References 73 Chapter 4. Isospin and G Parity 75 4.1 Isospin 75 4.1.1 The concept of isospin 75 4.1.2 Isospin transformation 78 4.1.3 The law of isospin conservation in strong interaction 83 4.1.4 The isospin of mesons and baryons 84 4.1.5 An example of isospin analysis of physical processes 88 4.2 Exchange Symmetry: Generalized Identity Principle 90 4.3 Isospin Violation 92 4.4 G Parity 93 References 97 Chapter 5. Quark Model of Hadrons 99 5.1 Mathematical Basics 100 5.1.1 Decomposition of SU(n) group representation product, Young tableau 100 5.1.2 ensor analysis of the SU(3) group 104 5.1.3 SU(3) group generators and Casmir operators 107 5.2 SU(3) Quark Model, the SU(3) Flavor Wave Functions for Mesons and Baxyons 109 5.2.1 The flavor wave functions for the pseudoscalar meson octet and singlet 111 5.2.2 Flavor wave functions for the vector meson octet and singlet 114 5.2.3 Flavor wave functions for baryon octet and decuplet 115 5.3 Color Degree of Freedom 122 5.3.1 The relationship of baryon spin and statistics 123 5.3.2 π°*rr 123 5.3.3 Measurement of R value in e+e- annihilation process 124 5.4 Mass Formula of Hadrons 127 5.5 Mixing of Meson Singlet and Octet 129 5.6 OZI Rule 134 5.7 SU(6) Symmetry 135 5.8 Orbital Excitation States and Radial Excitation States,Multi-quark States and Exotic States 137 5.8.1 Orbital and radial excitation states 137 5.8.2 Multi-quark states and exotic states 138 5.9 The Discovery of c,b,t Quarks 139 5.10 Quark Confinement 140 References 141 Chapter 6. Electromagnetic Interaction 143 6.1 QED and Its Feynman Rule 144 6.2 M0ller Scattering 149 6.3 Bhabha Scattering 154 6.4 The Electromagnetic Form Factors of Nucleons 156 6.4.1 Electron-proton elastic scattering assuming proton being a point particle 157 6.4.2 Elastic scattering of electron-proton 159 6.5 Inelastic Scattering of Electron-Proton 166 6.5.1 Structure function of inelastic scattering 166 6.5.2 The structure function applied to elastic scattering 169 6.6 The Parton Model for Nucleons 171 6.7 The Unification of Parton and Quark Model 174 References 177 Chapter 7. Weak Interactions 179 7.1 Looking Back to History 179 7.2 Classification of Weak Decays 181 7.3 Nuclear β Decay 183 7.4 The Discovery of Parity Violation 185 7.4.1 *-θ Puzzle 185 7.4.2 Parity violation in β decays of cobalt 60 nuclei 186 7.5 The V-A Theory of Weak Interactions 187 7.5.1 Pure leptonic decay 187 7.5.2 Semi-leptonic decay 189 7.6 Cabibbo Theory and GIM Mechanism 191 7.7 Kobayashi-Maskawa Model 194 7.8 The Limitation of the Four Fermion Point-like Interactions and the Intermediate Vector Bosons 196 7.9 Conservation of Vector Current 198 7.10 Chiral Symmetry Breaking and PC AC 201 7.11 Mixing of Neutral Mesons and CP Violation 205 7.11.1 Quantum mechanical description 205 7.11.2 K°-*°mixing and CP violation 212 7.11.3 B°-*°mixing and CP violation 224 7.11.4 D°-*°mixing and CP violation 238 References 243 Chapter 8. Gauge Theory of Electroweak Unification 247 8.1 The Higgs Mechanism 248 8.2 Yang