Non-Stationary Measurements of Chiral Magnetic Effect

TL;DR

This paper examines the Chiral Magnetic Effect through quantum measurement theory, highlighting how anisotropy in electric current fluctuations can arise from various factors like chemical potential, measurement duration, or magnetic field lifetime, all linked to the anomaly.

Contribution

It introduces a quantum measurement perspective to analyze non-stationary Chiral Magnetic Effect and clarifies the indistinguishability of anisotropy sources related to the anomaly.

Findings

Anisotropy from chemical potential is indistinguishable from that caused by measurement time.

The framework connects anisotropy to the abelian triangle anomaly.

Discussion of P-odd effects in heavy ion collisions where CME is absent.

Abstract

We discuss Chiral Magnetic Effect from quantum theory of measurements point of view for non-stationary measurements. The effect of anisotropy for fluctuations of electric currents in magnetic field is addressed. It is shown that anisotropy caused by nonzero axial chemical potential is indistinguishable in this framework from anisotropy caused by finite measurement time or finite lifetime of the magnetic field, and in all cases it is related to abelian triangle anomaly. Possible P-odd effects for central heavy ions collisions (where Chiral Magnetic Effect is absent) are discussed in this context.