Irreducible unitary representations of the Poincaré group are labelled by (m² ≥ 0, spin/helicity). Provides the Lorentz-covariant meaning of 'elementary particle'.
Irreducible unitary representations of the Poincaré group are labelled by (m² ≥ 0, spin/helicity). Provides the Lorentz-covariant meaning of 'elementary particle'.