Introduction to Elementary Particles

《粒子物理导论（英文版）》侧重于粒子物理学的基础知识，同时尽可能多地涵盖前沿进展。详细介绍了粒子的对称性原理、性质和分类、强子的夸克模型以及粒子间的相互作用。进一步提出了电磁和弱相互作用的统一理论和强相互作用的规范理论——量子色动力学（QCD）。在弱相互作用部分，系统地介绍了电中性粒子和中性K介子、中性B介子和中性D介子的反粒子的混合以及CP不守恒。在强相互作用部分，简要讨论了电荷、奇异态、胶体和混杂态、晶格规范理论。还介绍了轻子系统的中微子振荡和CP破坏。此外，《粒子物理导论（英文版）》还简要介绍了标准模型之外的几种新模型，如大统一理论和超对称模型。*后介绍了宇宙学与粒子物理关系的基本内容

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