Particle Physics (Manchester Physics Series)

An accessible and carefully structured introduction to Particle Physics, including important coverage of the Higgs Boson and recent progress in neutrino physics. Fourth edition of this successful title in the Manchester Physics series Includes information on recent key discoveries including: An account of the discovery of exotic hadrons, byond the simple quark model; Expanded treatments of neutrino physics and CP violation in B-decays; An updated account of ‘physics beyond the standard model', including the interaction of particle physics with cosmology Additional problems in all chapters, with solutions to selected problems available on the book's website Advanced material appears in optional starred sections Particle Physics......Page 3 Contents......Page 9 Editors' preface to the Manchester Physics Series......Page 15 Authors' preface......Page 17 Suggested Short Course......Page 19 Illustrations......Page 21 Physical Constants, Conversion Factors and Natural Units ......Page 23 1.1 Introduction......Page 25 1.2.1 Relativistic wave equations......Page 27 1.2.2 Hole theory and the positron......Page 30 1.3 Interactions and Feynman diagrams......Page 33 1.3.1 Basic electromagnetic processes......Page 34 1.3.2 Real processes......Page 35 1.3.3 Electron–positron pair production and annihilation......Page 37 1.4.1 Range of forces......Page 39 1.4.2 The Yukawa potential......Page 41 1.4.3 The zero-range approximation......Page 42 1.5 Units and dimensions......Page 43 2.1 Lepton multiplets and lepton numbers......Page 48 2.1.1 Electron neutrinos......Page 49 2.1.2 Further generations......Page 52 2.2.1 W± and Z0 exchange......Page 55 2.2.2 Lepton decays and universality......Page 57 2.3.1 Neutrino mixing......Page 59 2.3.2 Neutrino oscillations......Page 62 2.3.3 Neutrino masses......Page 70 2.3.4 Lepton numbers revisited......Page 72 3 Quarks and hadrons......Page 76 3.1 Quarks......Page 77 3.2 General properties of hadrons......Page 79 3.3 Pions and nucleons......Page 82 3.4 Strange particles, charm and bottom......Page 85 3.5 Short-lived hadrons......Page 90 3.6 Allowed and exotic quantum numbers......Page 96 4.1 Overview......Page 101 4.2 Accelerators and beams......Page 103 4.2.1 Linear accelerators......Page 104 4.2.2 Cyclic accelerators......Page 105 4.2.3 Fixed-target machines and colliders......Page 107 4.2.4 Neutral and unstable particle beams......Page 109 4.3.1 Short-range interactions with nuclei......Page 110 4.3.2 Ionisation energy losses......Page 113 4.3.3 Radiation energy losses......Page 116 4.3.4 Interactions of photons in matter......Page 117 4.3.5 Ranges and interaction lengths......Page 118 4.4 Particle detectors......Page 119 4.4.1 Introduction......Page 120 4.4.2 Gaseous ionisation detectors......Page 121 4.4.3 Semiconductor detectors......Page 127 4.4.4 Scintillation counters......Page 128 4.4.5 Čerenkov counters and transition radiation......Page 129 4.4.6 Calorimeters......Page 133 4.5 Detector systems and accelerator experiments......Page 136 4.5.1 Discovery of the W± and Z0 bosons......Page 137 4.5.2 Some modern detector systems......Page 141 4.6 Non-accelerator experiments......Page 145 5 Space–time symmetries......Page 150 5.1 Translational invariance......Page 151 5.2.1 Angular momentum conservation......Page 153 5.2.2 Classification of particles......Page 156 5.2.3 Angular momentum in the quark model......Page 158 5.3 Parity......Page 159 5.3.1 Leptons and antileptons......Page 161 5.3.2 Quarks and hadrons......Page 163 5.3.3 Parity of the charged pion......Page 164 5.3.4 Parity of the photon......Page 165 5.4 Charge conjugation......Page 166 5.4.1 π0 and η decays......Page 168 5.5 Positronium......Page 169 *5.5.1 Fine structure......Page 171 *5.5.2 C parity and annihilations......Page 172 *5.6 Time reversal......Page 173 5.6.1 Principle of detailed balance......Page 175 5.6.2 Spin of the charged pion......Page 176 6 The quark model......Page 179 6.1 Isospin symmetry......Page 180 6.1.1 Isospin quantum numbers......Page 181 6.1.2 Allowed quantum numbers......Page 182 6.1.3 An example: the sigma (Σ) baryons......Page 183 6.1.4 The u, d quark mass splitting......Page 185 6.2.1 The light mesons......Page 186 6.2.2 The light baryons......Page 188 *6.2.3 Baryon magnetic moments......Page 191 *6.2.4 Hadron mass splittings......Page 193 6.3 The L = 0 heavy quark states......Page 198 6.4 Colour......Page 201 6.4.1 Colour charges and confinement......Page 202 *6.4.2 Colour wavefunctions and the Pauli principle......Page 206 6.5 Charmonium and bottomonium......Page 208 6.5.1 Charmonium......Page 209 *6.5.3 The quark–antiquark potential......Page 213 7.1 Quantum chromodynamics......Page 217 7.1.1 The strong coupling constant......Page 221 7.1.2 Screening, antiscreening and asymptotic freedom......Page 223 *7.1.3 Exotic hadrons......Page 225 *7.1.4 The quark–gluon plasma......Page 232 7.2 Electron–positron annihilation......Page 234 7.2.1 Two-jet events......Page 235 7.2.2 Three-jet events......Page 237 7.2.3 The total cross-section......Page 238 8.1 Elastic electron scattering: the size of the proton......Page 241 8.1.1 Static charge distributions......Page 242 8.1.2 Proton form factors......Page 243 *8.1.3 The basic cross-section formulas......Page 245 8.2 Inelastic electron and muon scattering......Page 246 8.2.1 Bjorken scaling......Page 248 8.2.2 The parton model......Page 250 8.2.3 Parton distributions and scaling violations......Page 252 8.3 Inelastic neutrino scattering......Page 255 8.3.1 Quark identification and quark charges......Page 258 *8.4 Other processes......Page 260 8.4.1 Lepton pair production......Page 263 8.4.2 Jets in pp collisions......Page 266 8.5 Current and constituent quarks......Page 267 9 Weak interactions: quarks and leptons......Page 272 9.1.1 W±–lepton interactions......Page 274 9.1.2 Lepton–quark symmetry and mixing......Page 278 9.1.3 W boson decays......Page 282 *9.1.4 Selection rules in weak decays......Page 283 9.2 The third generation......Page 286 9.2.1 More quark mixing......Page 287 9.2.2 Properties of the top quark......Page 289 *9.2.3 Discovery of the top quark......Page 291 10 Weak interactions: electroweak unification......Page 300 10.1.1 The basic vertices......Page 301 10.1.2 The unification condition and the W± and Z0 masses......Page 303 10.1.3 Electroweak reactions......Page 305 10.1.4 Z0 formation: how many generations are there?......Page 308 10.2 Gauge invariance and the Higgs boson......Page 311 10.2.1 Unification and the gauge principle......Page 313 10.2.2 Particle masses and the Higgs field......Page 314 10.2.3 Properties of the Higgs boson......Page 318 10.2.4 The discovery of the Higgs boson......Page 321 11.1 P violation, C violation and CP conservation......Page 332 11.1.1 Muon decay symmetries......Page 334 11.1.2 Left-handed neutrinos and right-handed antineutrinos......Page 336 11.1.3 Pion and muon decays revisited......Page 338 11.2.1 CP eigenstates of neutral kaons......Page 340 11.2.2 The discovery of CP violation......Page 343 *11.2.3 CP-violating K0 decays......Page 345 11.2.4 Flavour oscillations and the CPT theorem......Page 348 11.2.5 Direct CP violation in decay rates......Page 352 11.2.6 B0 − B0 mixing......Page 353 *11.2.7 CP violation in interference......Page 359 *11.2.8 Derivation of the mixing formulas......Page 362 11.3 CP violation in the standard model......Page 364 12 Beyond the standard model......Page 370 12.1 Grand unification......Page 371 12.1.2 The weak mixing angle......Page 373 12.1.3 Proton decay......Page 374 12.2 Supersymmetry......Page 378 12.2.1 The search for supersymmetry......Page 380 12.3 Strings and things......Page 382 12.4.1 Dark matter......Page 384 12.4.2 Matter–antimatter asymmetry......Page 391 12.4.3 CP violation and electric dipole moments......Page 393 12.4.4 Axions and the strong CP problem......Page 395 12.5 Dirac or Majorana neutrinos?......Page 397 12.5.1 Double beta decay......Page 399 A.1 The Lorentz transformation for energy and momentum......Page 407 A.2.1 Beam energies and thresholds......Page 409 A.2.2 Masses of unstable particles......Page 411 *A.3 Transformation of the scattering angle......Page 412 B.1 Rates and cross-sections......Page 416 B.2 The total cross-section......Page 418 B.3 Differential cross-sections......Page 419 *B.4 The scattering amplitude......Page 421 B.5 The Breit–Wigner formula......Page 424 *B.5.1 Decay distributions......Page 425 *B.5.2 Resonant cross-sections......Page 428 Appendix *C The isospin formalism......Page 432 C.1 Isospin operators......Page 433 C.3 Isospin multiplets......Page 435 C.3.1 Hadron states......Page 436 C.4 Branching ratios......Page 438 C.5 Spin states......Page 440 Appendix D Gauge theories......Page 442 D.1 Electromagnetic interactions......Page 443 D.2 Gauge transformations......Page 444 D.3 Gauge invariance and the photon mass......Page 445 D.4 The gauge principle......Page 447 D.5.1 Charge and current densities......Page 449 D.5.2 Spin-0 bosons......Page 451 D.5.3 Spontaneous symmetry breaking......Page 452 D.6 Quantum chromodynamics......Page 453 D.7.1 Weak isospin......Page 458 D.7.2 Gauge invariance and charged currents......Page 460 D.7.3 The unification condition......Page 461 D.7.4 Spin structure and parity violation......Page 464 Appendix E Answers to selected questions......Page 467 References......Page 472 Index......Page 475 Supplemental Images......Page 481 EULA ......Page 485