W to Z mass ratio = 0.881 45 (dimensionless)

Value
0.881 45
Unit
(dimensionless)
Uncertainty
0.000 13
Copy-ready
0.88145

The ratio of the W boson mass to the Z boson mass.

Fixed by the weak mixing angle at tree level; a cross-check of the electroweak theory.

NIST, Fundamental Physical Constants — Complete Listing (2022 CODATA adjustment), retrieved 2026-07-26.

Electrical, thermal and X-ray constants

Angstrom starConductance quantumCopper x unitElectron charge to mass quotientFermi coupling constantFirst radiation constantHartree energyJosephson constantLattice parameter of siliconLattice spacing of ideal Si (220)Loschmidt constant (273.15 K, 101.325 kPa)Magnetic flux quantumMolar mass constantMolar mass of carbon-12Molar Planck constantMolar volume of siliconMolybdenum x unitNeutron-proton mass differenceProton charge to mass quotientQuantum of circulationSackur-Tetrode constant (1 K, 101.325 kPa)Second radiation constantVon Klitzing constantWeak mixing angleWien frequency displacement law constantW to Z mass ratio

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All physical constants

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