W and Z Bosons

Weak force carriers: charged and neutral currents, decay modes

Boson type
Decay rate 1.5×
Energy (GeV) 91 GeV
80.4
Mass (GeV/c²)
2.085
Width Γ (GeV)
3.16
Lifetime (×10⁻²⁵s)
67%
Hadronic BR

About

The W± and Z⁰ bosons are the massive carriers of the weak nuclear force, discovered at CERN in 1983 by Carlo Rubbia and Simon van der Meer (Nobel 1984). The W bosons mediate charged-current interactions — changing quark and lepton flavors — while the Z⁰ mediates neutral-current interactions. Their large masses (~80–91 GeV) arise from the Higgs mechanism, giving the weak force its characteristically short range (~10⁻¹⁸ m).