# Charge conjugation and time reversal in the SM

1. ### Einj

443
Hi everyone. I have a doubt on charge conjugation symmetry. Consider the Standard Model lagrangian with just the gauge and the fermionic part (no Higgs and no Yukawa). This is invariant under $SU(3)_C\times SU(2)_L\times SU(2)_R\times U(1)_Y$. Moreover, as any other field theory, it is $CPT$ invariant.

Since, however $P$ is clearly violated by the asymmetry in the left-right fields we know that $CT$ must be violated too.

What can we say about $C$ and $T$ independently?