Chiral magnetic effect reveals the topology of gauge fields in heavy-ion collisions

TL;DR

This paper discusses how the chiral magnetic effect observed in heavy-ion collisions can reveal the topological structure of gauge fields in QCD, providing insights into fundamental physics phenomena like baryon asymmetry.

Contribution

It proposes using heavy-ion collision experiments, such as Zr-Zr and Ru-Ru isobars, to directly observe topological transitions in QCD vacuum.

Findings

Chiral magnetic effect links topological transitions to observable electric currents.

Heavy-ion collisions can serve as a laboratory to study QCD vacuum topology.

Potential implications for understanding baryon asymmetry and condensed matter physics.

Abstract

The topological structure of vacuum is the cornerstone of non-Abelian gauge theories describing strong and electroweak interactions within the standard model of particle physics. However, transitions between different topological sectors of the vacuum (believed to be at the origin of the baryon asymmetry of the Universe) have never been observed directly. An experimental observation of such transitions in Quantum Chromodynamics (QCD) has become possible in heavy-ion collisions, where the chiral magnetic effect converts the chiral asymmetry (generated by topological transitions in hot QCD matter) into an electric current, under the presence of the magnetic field produced by the colliding ions. The Relativistic Heavy Ion Collider program on heavy-ion collisions such as the Zr-Zr and Ru-Ru isobars, thus has the potential to uncover the topological structure of vacuum in a laboratory experiment. This discovery would have far-reaching implications for the understanding of QCD, the origin of the baryon asymmetry in the present-day Universe, and for other areas, including condensed matter physics.