Parity Violation
The discovery that the weak nuclear force distinguishes between left-handed and right-handed spatial orientations, violating spatial mirror symmetry (P-parity).
Governing formula
P |Ψ(x, y, z)⟩ = - |Ψ(-x, -y, -z)⟩ (Violated in weak decays)
SI unit
Symmetry Violation
In depth
Discovered experimentally by Chien-Shiung Wu in 1956 using polarized Cobalt-60 beta decay. The weak force couples exclusively to left-handed fermions and right-handed antifermions, maximally violating parity symmetry.
Examples in the real world
Observing preferential electron emission opposite to nuclear spin alignment during Cobalt-60 beta decay.