Chiral Magnetic Spiral

TL;DR

This paper proposes that strong magnetic fields in chirally broken phases induce inhomogeneous, spiral-like currents of charge and chirality along the magnetic field, potentially explaining observed charge fluctuations in heavy ion collisions.

Contribution

It introduces the concept of a chiral magnetic spiral, a novel inhomogeneous current pattern induced by strong magnetic fields at finite baryon density or chirality imbalance.

Findings

Predicts inhomogeneous spiral currents of charge and chirality along magnetic fields.

Suggests the chiral magnetic spiral contributes to charge fluctuation signals in heavy ion collisions.

Identifies the spiral as a gapless excitation transporting currents along the magnetic field.

Abstract

We argue that the presence of a very strong magnetic field in the chirally broken phase induces inhomogeneous expectation values, of a spiral nature along the magnetic field axis, for the currents of charge and chirality, when there is finite baryon density or an imbalance between left and right chiralities. This "chiral magnetic spiral" is a gapless excitation transporting the currents of (i) charge (at finite chirality), and (ii) chirality (at finite baryon density) along the direction of the magnetic field. In both cases it also induces in the transverse directions oscillating currents of charge and chirality. In heavy ion collisions, the chiral magnetic spiral possibly provides contributions both to the out-of-plane and the in-plane dynamical charge fluctuations recently observed at RHIC.