Helical magnetic effect and the chiral anomaly

In the presence of fluid helicity $\boldsymbol{v} \cdot \boldsymbol{\omega}$, magnetic field induces an electric current form $\boldsymbol{j} = C_{\rm HME} (\boldsymbol{v} \boldsymbol{\omega}) \boldsymbol{B}$. This is helical effect (HME). We show that for massless Dirac fermions with charge $e=1$, transport coefficient $C_{\rm HME}$ fixed by chiral anomaly $C=1/(2\pi^2)$ as C/2$ independently interactions. conjecture magnetovorticity coupling local vector charge, $n C_{B \omega} \boldsymbol{B} related to $C_{B C/2$. also discuss condition emergence plasma instability originates from HME.