A. Zee, Quantum Field Theory in a Nutshell · Problem V.7.13

Field Theory Redux

Physics — QFT

Problem

Prove that higher order corrections do not change the chiral anomaly ∂μJ5μ=[1/(4π)2]ϵμνλσtrFμνFλσ\partial_\mu J_5^\mu = [1/(4\pi)^2]\epsilon^{\mu\nu\lambda\sigma} \text{tr} F_{\mu\nu}F_{\lambda\sigma} (I have rescaled A→(1/g)AA \to (1/g)A). [Hint: Integrate over spacetime and show that the left hand side is given by the number of right-handed fermion quanta minus the number of left-handed fermion quanta, so that both sides are given by integers.]

Browse the problem library