Anomalous Chiral Transport in Heavy Ion Collisions

TL;DR

This paper reviews the theoretical and experimental progress in understanding the Chiral Magnetic Effect (CME), a phenomenon where chiral anomaly induces observable transport currents in heavy ion collisions, linking fundamental quantum anomalies to macroscopic effects.

Contribution

It provides a comprehensive overview of recent theoretical developments and experimental searches for CME in heavy ion collisions, highlighting new insights into chiral anomaly manifestations.

Findings

Recent experimental evidence supports the existence of CME in heavy ion collisions.

Theoretical models have advanced understanding of anomaly-induced transport phenomena.

Ongoing research aims to clarify the conditions under which CME occurs.

Abstract

Chiral anomaly is a very fundamental aspect of quantum theories with chiral fermion, from the Standard Model to supersymmetric field theories or even string theories. How such microscopic anomaly manifests itself in a macroscopic many-body system with chiral fermions, is a highly nontrivial question that has recently attracted significant interest. As it turns out, unusual transport currents can be induced by chiral anomaly under suitable conditions in such systems, with the notable example of the Chiral Magnetic Effect (CME) where a vector current (e.g. electric current) is generated along an external magnetic field. The CME has been enthusiastically studied in two very different physical systems: the Dirac and Weyl semimetals in condensed matter physics as well as the quark-gluon plasma in heavy ion collisions. In this contribution, we report the latest theoretical and experimental status for the search of CME in heavy ion collisions.