Chiral transformation
= Chiral transformation
A chiral transformation rotates a Dirac field by $\psi\mapsto e^{i\alpha\gamma^5}\psi$. A massless Dirac kinetic term is invariant under a global rotation, while a mass term is not.
= Chiral transformation
A chiral transformation rotates a Dirac field by $\psi\mapsto e^{i\alpha\gamma^5}\psi$. A massless Dirac kinetic term is invariant under a global rotation, while a mass term is not.