Standard Model and Beyond · Problem 2.28

Lie Groups, Lie Algebras, and Symmetries

Physics — Particle Physics · cp-invariance-chiral-interaction

Problem

Consider the interaction

\mathcal{L}_I = g\left(\bar{\psi}_{aL}\psi_{bR}\phi + \bar{\psi}_{bR}\psi_{aL}\phi^\dagger\right)

between distinct fermions

\psi_a

and

\psi_b

, where

\phi

is a complex scalar and

g

is real. Show that the Lagrangian violates

P

and

C

, but is

CP

invariant.