Axial current (source code)

= Axial current
{title2=$J_A^\mu$}
{wiki}

For massless Dirac fermions, the classical axial current is $J_A^\mu=\bar\psi\gamma^\mu\gamma^5\psi$. The chiral anomaly makes its divergence proportional to $F_{\mu\nu}{}^\star F^{\mu\nu}$.