Anomalous Transport from Effective Field Theory

TL;DR

This paper systematically studies chiral effects and anomalies using an Effective Field Theory approach, revealing their unified origin, mass corrections, and finite-temperature behavior.

Contribution

It provides a unified computation of chiral effects and anomalies, including new mass corrections, and clarifies their relation beyond simple coefficient identification.

Findings

Chiral effects arise naturally from a unified EFT computation.

Mass corrections to chiral effects are identified.

Finite temperature currents cannot be derived solely from Chern-Simons terms.

Abstract

A systematic study of chiral effects is presented using an Effective Field Theory framework. By integrating out a massive Dirac fermion at finite temperature in presence of vector and axial background fields, the currents and their anomalies are computed from the path-integral. Chiral effects previously considered separately naturally arise in a unified computation, including new mass corrections. The link between each anomalous transport effect and the anomalies is clearly established, beyond the identification of their coefficients. In particular, we can appreciate how these effects are sourced by the anomalous nature of the theory even in configurations where the anomaly itself vanishes. The consistent and covariant anomalies are both encapsulated in master formulae for the currents which result from a careful treatment of the regularisation. It is finally found that, at finite temperature, the physical currents cannot be inferred simply from the Chern-Simons terms whose divergence reproduce the chiral anomalies.