Standard Model and Beyond · Problem 7.9

The Standard Electroweak Theory

Physics — Particle Physics · axial-current-pion-matrix-element

Problem

Use reflection invariance to show that

\langle \pi^i(\vec{p}_2) | A^j_\mu | \pi^k(\vec{p}_1) \rangle

, the matrix element of the axial current between single pion states, is zero.