Phyz
Particle physics, explained step by step
Phyz
Particle physics notes
Work through particle physics one step at a time, starting with classical mechanics. Each chapter explains the ideas and equations used in the next.
Contents
Chapters
Read in order, or jump directly to the idea you need.
3 chapters
Foundations
Describe motion, then introduce quantum states and energy levels.
Classical Mechanics
Describe motion with position and momentum, then derive Hamilton’s equations.
Read chapterFirst Quantization
Represent position and momentum as operators acting on quantum states.
Read chapterHarmonic Oscillator
Calculate equally spaced energy levels with creation and annihilation operators.
Read chapter3 chapters
Relativity
Apply special relativity to quantum wave equations.
Special Relativity
Relate measurements in moving frames using Lorentz transformations.
Read chapterRelativistic QM
Derive a relativistic wave equation and examine its probability density.
Read chapterThe Dirac Equation
Derive the electron’s wave equation and interpret its spinor solutions.
Read chapter3 chapters
Quantum fields
Describe particles as quanta of fields.
Fields and Quanta
Use quantum fields to describe states with different particle numbers.
Read chapterAction and Lagrangians
Derive field equations and conserved quantities from an action.
Read chapterField Quantization
Quantize free scalar and spinor fields, then calculate their propagators.
Read chapter4 chapters
Quantum Electrodynamics
Calculate how electrons and photons interact.
Quantum Electrodynamics
Derive the electron–photon coupling from local phase symmetry.
Read chapterFrom Lagrangian to Experiment
Connect a scattering amplitude to a measurable cross section.
Read chapterPerturbation Theory
Approximate scattering amplitudes by expanding in the interaction strength.
Read chapterFeynman Rules for QED
Assign a mathematical factor to each part of a Feynman diagram.
Read chapter4 chapters
Electroweak
Study the weak force and its relation to electromagnetism.
Symmetries
Build the route from spatial rotations to SU(2), Lorentz spinors, and chirality.
Read chapterWeak Interaction
Connect beta decay to chiral currents, Yang–Mills fields, and W-boson exchange.
Read chapterElectroweak Unification
Recover photon and Z couplings from weak isospin, hypercharge, and neutral-field mixing.
Read chapterHiggs Mechanism
Outline: explain how the Higgs field gives mass to the W and Z bosons.
Read chapter2 chapters
Strong & Standard Model
Study the strong force and combine the Standard Model interactions.
5 chapters
Path Integrals (Optional)
Optional background on sums over histories, fermion signs, gauge freedom, and loop corrections. Explore these extras after the Standard Model.
Path Integrals in Quantum Mechanics
Connect sums over possible histories to quantum interference and classical motion.
Read chapterPath Integrals for Fields
See how field histories lead to the same propagators and Feynman diagrams.
Read chapterFermionic Path Integrals
Understand how anticommuting variables preserve fermion exchange signs.
Read chapterGauge Fixing
Explain why redundant potentials require a gauge choice when calculating propagation.
Read chapterRenormalization at One Loop
Connect regulated loop corrections to measured masses and interaction strengths.
Read chapter1 chapter
Final Recap
Connect the full journey from classical motion to quantum fields and experimental predictions.
5 chapters
Math Refresher
Reference for the mathematical tools used across the chapters. Skim ahead, or revisit a topic when it appears.
Calculus
Derivatives, integration by parts, Taylor series, and vector calculus.
Read chapterComplex Numbers
Euler's formula, phases, and the Fourier transform.
Read chapterLinear Algebra
Matrices, eigenvalues, and bra-ket notation.
Read chapterIndex Notation and Tensors
Einstein summation, the metric, and contractions.
Read chapterGroups and Symmetry
U(1), SU(2), generators, and why order matters.
Read chapter