Editing Chirality (physics) (section)

{{Short description|Property of particles related to spin}}
A '''chiral''' phenomenon is one that is not identical to its [[mirror image]] (see the article on [[Chirality (mathematics)|mathematical chirality]]). The [[Spin (physics)|spin]] of a [[Elementary particle|particle]] may be used to define a '''handedness''', or helicity, for that particle, which, in the case of a massless particle, is the same as chirality. A [[Symmetry (physics) | symmetry transformation]] between the two is called [[parity (physics)|parity]] transformation. Invariance under parity transformation by a [[Dirac fermion]] is called '''chiral symmetry'''.