Questions tagged [chirality]
Chirality is defined through the ±1 eigenvalue under action of γ<sup>5</sup> on ψ, a Dirac field thus projected into its left- or right-handed component by the projection operators (1−γ<sup>5</sup>)/2 or (1+γ<sup>5</sup>)/2 on ψ. For massless particles (only!) chirality coincides with [helicity], a notion which is frame-dependent, and hence ambiguous for massive particles. Avoid using instead of the [helicity] tag: the projectors *must* be implied.