# Tag Info

First, in order to show the invariance of the term $\bar{\psi}_L \phi \psi_R$, you have to transform respectively: $\psi_L \to e^{-i \alpha^a(x) \frac{\sigma_a}{2} -i \alpha(x) \frac{Y}{2}} \psi_L$ $\psi_R \to e^{-i \alpha(x) \frac{Y}{2}} \psi_R$ $\phi \to e^{-i \alpha^a(x) \frac{\sigma_a}{2} -i \alpha(x) \frac{Y}{2}} \phi$ (a=1,2,3) so that the ...