Standard Model gauge symmetry and electroweak mass mechanism
The minimal Standard Model has gauge group SU(3)_C×SU(2)_L×U(1)_Y with strong and electroweak gauge sectors.
Key knowledge
The minimal Standard Model has gauge group SU(3)_C×SU(2)_L×U(1)_Y with strong and electroweak gauge sectors. A Higgs doublet vacuum expectation value leaves SU(3)_C×U(1)_em unbroken. At tree level in ħ=c=1 units, the weak boson masses are M_W=gv/2 and M_Z=v√(g²+g′²)/2, with tanθ_W=g′/g and e=g sinθ_W. Gauge symmetry and the scalar sector supply structure beyond a list of particle carriers.
Values and equations
SU(3)_C×SU(2)_L×U(1)_Y→SU(3)_C×U(1)_em; M_W=gv/2; M_Z=v√(g²+g′²)/2; tanθ_W=g′/g; e=g sinθ_W (ħ=c=1)
- SU(3)_C,SU(2)_L,U(1)_Y,U(1)_em
- Color, weak-isospin, hypercharge and electromagnetic gauge groups
- M_W,M_Z,v
- Boson masses and Higgs vacuum scale in the declared energy-unit convention GeV
- g,g′,e
- Dimensionless gauge/charge couplings in natural units
- θ_W
- Weak mixing angle rad
Conditions and scope
- Minimal renormalizable gauge/Higgs model; M_W,M_Z and v use the natural-unit energy convention, and e,g,g′ are dimensionless couplings in that convention. They are not the SI charge measured in coulombs in other records.
- Tree formulas omit loop corrections and contain parameters requiring measurement. This minimal model excludes gravity and dark-matter explanations and has massless neutrinos without extension; observed neutrino oscillations require additional mass physics. No current fitted parameter values or exhaustive QFT action are asserted.
Sources · 2
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
PDG: Electroweak Model and Constraints on New Physics: Section 10.1, printed pages 1–2, equations 10.1–10.5: electroweak gauge doublets/singlets, Higgs breaking, mixing and tree boson masses. Resource uses the 2025 URL with a 15 April 2026 PDF footer; no time-dependent fit table is used. PDG: Neutrino Masses, Mixing, and Oscillations (2025): Section 14.1, printed pages 1–2: full SU(3)×SU(2)×U(1) gauge group and minimal model's absent neutrino mass; the specific extension mechanism is not declared established by this reference.
2026-10-10 · Independent AI editorial review: All 136 unique authored Physics compact statements, all hypotheses and displayed equations/variable/units tables, all 192 Physics-origin semantic links, exact 165 author inspection matrix and mapped retained conceptual claims have been independently read. Three Physics-tagged Measurement realization records are delegated to root Measurement review. Scientific source verification combines exact author section inspection with independent whole compact-content/semantic review and targeted primary rechecks recorded below; it does not claim each full source body was independently reread. Independent AI editorial review is not human specialist certification or experimental replication. Field inventory is approved after independently reviewing the two added source-inspected band-construction methods. Receipt: physics-independent-content-inventory-review.1.
Entry details
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- physics-standard-model-gauge-structure
- Revision
- university-core.1
- Structured reference record
- University core expansion