ELEMENTARY PHYSICS
CONTENTS EXECUTIVE SUMMARY 1 1 INTRODUCTION 11 ELEMENTARY PARTICLE PHYSICS 12 WHAT WE KNOW 12 WHAT WE WANT TO KNOW 15 THE TOOLS OF ELEMENTARY PARTICLE PHYSICS 15 THE FUTURE TOOLS OF ELEMENTARY PARTICLE PHYSICS 16 2 WHAT IS ELEMENTARY PARTICLE PHYSICS 18 WHAT IS AN ELEMENTARY PARTICLE 19 HOW MANY KINDS OF ELEMENTARY PARTICLES ARE THERE 19 THE SIZE OF ELEMENTARY PARTICLES 23 ELEMENTARY PARTICLES AND HIGH ENERGY 23 THE KNOWN BASIC FORCES AND FUNDAMENTAL PARTICLES 25 THE FOUR BASIC FORCES 25 THE KNOWN FAMILIES OF ELEMENTARY PARTICLES 26 THE FORCE CARRYING PARTICLES 27 THE LEPTONS 27 THE QUARKS 28 THE HADRONS 29 PARTICLES AND ANTIPARTICLES 30 COLLISIONS AND DECAYS 31 COLLISIONS OF PARTICLES 31 COLLISION DIAGRAMS 31 COLLISIONS AND INTERACTIONS 33 SPONTANEOUS DISINTEGRATION OF PARTICLES 35 CONSERVATION LAWS AND SYMMETRY IDEAS 35 WHAT ARE CONSERVATION LAWS 35 SYMMETRY AND INVARIANCE 36 SYMMETRY BREAKING 39 EXPERIMENTS ACCELERATORS AND PARTICLE DETECTORS 40 EXPERIMENTAL METHODS IN ELEMENTARY PARTICLE PHYSICS 40 EXPERIMENTS AT FIXED TARGET ACCELERATORS 40 FIXED TARGET ACCELERATORS 41 TARGETS 42 PARTICLE DETECTORS FOR CHARGED PARTICLES 42 SECONDARY PARTICLE BEAMS 43 PARTICLE COLLIDERS 43 EXPERIMENTS AT PARTICLE COLLIDERS 46 THE DECAYS OF PARTICLES 47 EXPERIMENTS IN ELEMENTARY PARTICLE PHYSICS WITHOUT ACCEL ERATORS 47 3 WHAT WE HAVE LEARNED IN THE PAST TWO DECADES 48 DEVELOPMENT OF THE QUARK MODEL OF HADRONS 48 THE BEGINNINGS OF THE QUARK MODEL 48 THE DISCOVERY OF THE CHARMED QUARK 50 CHARMONIUM STATES 51 DISCOVERY OF THE THIRD GENERATION OF LEPTONS AND QUARKS 53 THE DISCOVERY OF THE TAU LEPTON 53 THE DISCOVERY OF THE BOTTOM QUARK 55 THE THIRD GENERATION 56 HOW QUARKS INTERACT 59 HADRON INTERACTIONS 59 LEPTON PROTON SCATTERING EXPERIMENTS 59 HADRON JETS 62 UNIFICATION OF THE WEAK AND ELECTROMAGNETIC INTERACTIONS 65 STRONG INTERACTION AMONG QUARKS 70 UNIFIED THEORIES 76 4 ELEMENTARY PARTICLE PHYSICS WHAT WE WANT TO KNOW 81 INTRODUCTION 81 THE PROBLEM OF MASS 83 WHERE DO ALL THESE MASS SCALES ORIGINATE 85 COMPOSITE QUARKS AND LEPTONS 86 UNIFICATION OF THE FUNDAMENTAL FORCES 86 INTERACTION OF HADRONS 87 USING EXISTING ACCELERATORS AND ACCELERATORS UNDER CONSTRUC TION 87 THE NEED FOR HIGHER ENERGY ACCELERATORS 91 SOME FUNDAMENTAL ISSUES 96 5 ACCELERATORS FOR ELEMENTARY PARTICLE PHYSICS 98 INTRODUCTION TO ACCELERATORS 98 THE WHY AND HOW OF ACCELERATORS 98 PARTICLE COLLIDERS 101 SUPERCONDUCTING MAGNETS IN ACCELERATORS 103 PROGRESS IN ACCELERATORS AND THE ENERGY FRONTIER 104 ELEMENTARY PARTICLE PHYSICS AND THE VARIETY OF ACCELERATORS 104 STUDY OF THE PROPERTIES OF KNOWN PARTICLES 104 STUDY OF THE KNOWN FORCES 106 TESTS OF NEW IDEAS AND THEORIES 107 THE SEARCH FOR NEW PARTICLES AND THE MASS SCALE 108 SEARCHES FOR CLUES TO PUZZLES AND EXPLORATION OF THE UNKNOWN 109 ACCELERATORS WE ARE USING AND BUILDING 110 PROTON ACCELERATORS FIXED TARGET 111 PROTON PROTON AND PROTON ANTIPROTON COLLIDERS AT CERN 113 THE 2 TEV PROTON ANTIPROTON COLLIDER AT FERMILAB 115 ELECTRON ACCELERATORS FIXED TARGET 115 CIRCULAR ELECTRON POSITRON COLLIDERS 115 THE TRISTAN AND LEP ELECTRON POSITRON CIRCULAR COLLID ERS 116 LINEAR ELECTRON POSITRON COLLIDERS 118 ELECTRON PROTON COLLIDERS 120 THE SUPERCONDUCTING SUPER COLLIDER A VERY HIGH ENERGY PROTON PROTON COLLIDER 120 PHYSICS GOALS 120 COLLIDER GOALS 121 DESIGN STUDIES 122 SUPERCONDUCTING MAGNETS 123 PRELIMINARY COLLIDER DESIGNS AND CONSIDERATIONS 124 SCHEDULE AND COST 127 RESEARCH AND DEVELOPMENT FOR VERY HIGH ENERGY LINEAR COL LIDERS 128 PHYSICS MOTIVATION 128 PRESENT TECHNOLOGY AND CONCEPTS 128 RESEARCH ON ADVANCED CONCEPTS FOR ACCELERATORS AND COLLID ERS 129 LINEAR ACCELERATORS AND COLLIDERS 129 ULTRAHIGH ENERGY CIRCULAR COLLIDERS 131 THE NEED FOR ADVANCED RESEARCH ON ACCELERATORS AND COL LIDERS 131 6 INSTRUMENTS AND DETECTORS FOR ELEMENTARY PARTICLE PHYSICS 132 INTRODUCTION 132 DETECTOR REQUIREMENTS AND PHYSICAL PRINCIPLES OF DETECTION 135 DETECTORS FOR COLLIDER EXPERIMENTS 139 CLOSE IN DETECTION VERTEX DETECTORS 140 CHARGED PARTICLE TRACKING CHAMBERS 141 IDENTIFICATION OF PARTICLE TYPES 143 CALORIMETRIC DETECTION AND ENERGY MEASUREMENT 143 DETECTORS IN FIXED TARGET EXPERIMENTS 144 SMALL OR SIMPLE FIXED TARGET EXPERIMENTS 144 LARGE OR COMPLEX FIXED TARGET EXPERIMENTS 147 BUBBLE CHAMBER 147 DATA REDUCTION AND COMPUTERS 149 FACILITIES AND DETECTORS FOR EXPERIMENTS NOT USING ACCELERA TORS 152 ATOMIC OPTICAL ELECTRONIC AND CRYOGENIC EXPERIMENTS 152 EXPERIMENTS USING RADIOACTIVE MATERIAL OR REACTORS 152 EXPERIMENTS USING COSMIC RAYS 153 THE SOLAR NEUTRINO EXPERIMENT 155 SEARCHES FOR THE DECAY OF THE PROTON 155 SUMMARY AND FUTURE PROSPECTS 156 7 INTERACTION WITH OTHER AREAS OF PHYSICS AND TECHNOLOGY 157 COSMOLOGY AND ASTROPHYSICS 158 COSMIC RAY PHYSICS 160 NUCLEAR PHYSICS 161 ATOMIC PHYSICS 164 CONDENSED MATTER THEORETICAL PHYSICS 165 OTHER APPLICATIONS OF ACCELERATORS 166 SYNCHROTRON RADIATION 166 ACCELERATORS IN MEDICINE 169 HIGH INTENSITY NEUTRON SOURCES 169 ACCELERATORS AND PLASMA PHYSICS 170 LARGE SCALE USES OF SUPERCONDUCTIVITY 170 SUPPORT AND STIMULATION OF NEW TECHNOLOGY 171 8 EDUCATION ORGANIZATION AND DECISION MAKING IN ELEMENTARY PARTICLE PHYSICS 172 HISTORICAL BACKGROUND 172 BEFORE 1960 172