Equations · equation
Standard Model Lagrangian
Particle Physics · 1975
- Equation
- ℒ = −¼F_μν·F^μν + iψ̄D̸ψ + ψ̄ᵢyᵢⱼψⱼφ + h.c. + |D_μφ|² − V(φ)
- Field
- Particle Physics
- Named After
- Sheldon Glashow · Abdus Salam · Steven Weinberg · and many hands
- Year
- 1975
Symbols
F_μν the force fields — photon, W, Z and the gluons · ψ the matter fields, quarks and leptons, in motion · yᵢⱼ the Yukawa couplings: matter meeting the Higgs and taking mass from it · φ the Higgs field itself, shaped by its potential · D_μ the covariant derivative, which is where the forces actually enter · h.c. the Hermitian conjugate. Compact notation throughout — written out, it runs to pages
Significance
Every known particle and every force except gravity, in one very compressed expression — the equation on CERN's coffee mugs. Assembled through the 1960s and 70s out of electroweak unification and quantum chromodynamics; its last missing piece, the Higgs boson, arrived in 2012. It is not unblemished: neutrinos have mass, which the model as written forbids, and the oscillation experiments that proved it in 1998 are the one confirmed crack in it. Everything else it has predicted has so far survived every test aimed at it.
Referenced by
constant
equation
event
theory
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