Particle Physics

Invariants, Symmetries and the Standard Model in 14 chapters — from “Scales, units and the four-momentum” to “Detectors, event reconstruction and claiming a discovery”.

Chapters

  1. Scales, units and the four-momentum
    • Muon survival and the Lorentz factor
    • Mass and momentum units
    • The four-vector and its invariant product
    • Four-momentum and the energy-momentum relation
    • Massless particles and the probe distance scale
    • Summary
    • Problems
  2. Invariant mass: decays, thresholds and the collider frame
    • Conservation of four-momentum
    • The invariant mass of a system
    • Centre-of-mass energy and collider reach
    • The production threshold
    • Two-body decay and decay length
    • Summary
    • Problems
  3. The particle zoo and the four interactions
    • The muon and a second generation
    • Quarks and leptons in three generations
    • Gauge bosons and four fundamental interactions
    • The weakness of gravity
    • Particle identity
    • The lifetime fingerprint
    • Summary
    • Problems
  4. Hadrons: baryons, mesons and their quark content
    • Hadrons from six quarks
    • Strangeness and quark-content arithmetic
    • Hadron spin from quark spins
    • Colour charge and the Δ++
    • Free quarks and hadron mass
    • Hadron identification from decay products
    • Summary
    • Problems
  5. Quantum numbers, conservation laws and allowed reactions
    • Additive quantum numbers
    • Charge, baryon and lepton family numbers
    • Flavour conservation by interaction
    • Allowed reactions and the two kinds of no
    • Supplying a missing product
    • Proton stability as a measurement
    • Summary
    • Problems
  6. Isospin: a symmetry used as bookkeeping
    • Symmetry as blindness
    • Isospin and hypercharge
    • Isospin multiplets and isospin breaking
    • The isospin rate ratio at the Δ
    • Hadrons on the weight diagram
    • Summary
    • Problems
  7. SU(3) flavour and the hadron multiplets
    • The spin-three-halves pattern with a gap
    • Three-flavour symmetry and the quark triangle
    • Multiplet combination by adding positions
    • The Omega-minus prediction and the Gell-Mann-Okubo relation
    • Flavour symmetry breaking and its limits
    • Summary
    • Problems
  8. Exchange, range and coupling: diagrams as bookkeeping
    • Dimensionless coupling and the lifetime puzzle
    • Particle exchange and the range of an interaction
    • The Feynman diagram as bookkeeping
    • Vertex counting and the order of rates
    • The weakness of the weak interaction
    • The limits of diagrams
    • Summary
    • Problems
  9. Parity, charge conjugation, time reversal and CPT
    • The parity operation and a mirror experiment
    • Intrinsic parity as a multiplicative quantum number
    • Charge conjugation, and a decay that never happens
    • Parity violation in cobalt-60
    • Time reversal, the CPT theorem and CP violation
    • Summary
    • Problems
  10. The Standard Model as a table you can predict from
    • The Standard Model table on one page
    • Reading the Standard Model table forwards
    • Counting the Standard Model parameters
    • Limits of the Standard Model
    • Summary
    • Problems
  11. Decay rates, cross sections and phase space
    • Decay width, partial width and lifetime
    • The cross section, defined by a measurement
    • Phase space and the room the products have
    • The golden-rule structure of a rate
    • Summary
    • Problems
  12. Resonances, widths and the Breit-Wigner line shape
    • The resonance as a bump in a scan
    • Breit-Wigner line shape and line width as lifetime
    • Resolution and natural width
    • Resonance parameters and the resonance as a particle
    • Summary
    • Problems
  13. Accelerators and colliders: energy, luminosity and reach
    • Production threshold and the design brief
    • Radiofrequency acceleration and dipole bending
    • Synchrotron radiation and the choice of collider
    • Luminosity and integrated luminosity
    • Machine specification for a physics goal
    • Summary
    • Problems
  14. Detectors, event reconstruction and claiming a discovery
    • Pile-up and one Higgs boson per second
    • Detector response in four layers
    • Missing transverse energy and event reconstruction
    • Poisson counting, background and event selection
    • Statistical significance and its limits
    • The 2012 diphoton discovery, end to end
    • Summary
    • Problems