Chern-Simons current and local parity violation in hot QCD matter
✍ Scribed by Dmitri E. Kharzeev
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- English
- Weight
- 157 KB
- Volume
- 830
- Category
- Article
- ISSN
- 0375-9474
No coin nor oath required. For personal study only.
✦ Synopsis
Non-Abelian gauge theories "live" in a space-time with non-trivial topology that can be characterized by an odd-dimensional Chern-Simons form. In QCD, Chern-Simons form is induced by the chiral anomaly and the presence of topological solutions; it opens a possibility for the breaking of P and CP invariances in strong interactions ("the strong CP problem"). While there is apparently no global P and CP violation in QCD, here I argue that topological fluctuations in hot quark-gluon matter can become directly observable in the presence of a very intense external magnetic field by inducing local P-and CP-odd effects. These phenomena can be described by using the Maxwell-Chern-Simons electrodynamics as an effective theory. Local P and CP violation in hot QCD matter can be observed in experiment through the "chiral magnetic effect" -the separation of electric charge along the axis of magnetic field that is created by the colliding relativistic ions. There is a recent evidence for the electric charge separation relative to the reaction plane of heavy ion collisions from the STAR Collaboration at RHIC.