August 25, 2008 | Kenji Fukushima, Dmitri E. Kharzeev, Harmen J. Warringa
The Chiral Magnetic Effect (CME) is a phenomenon where an electromagnetic current is generated along an external magnetic field in a quark-gluon plasma due to the axial anomaly. This effect arises from topological charge-changing transitions, which induce chirality in the plasma. The authors introduce a chiral chemical potential, denoted as \(\mu_5\), to mimic these transitions and study the equilibrium response of the plasma to an applied magnetic field. They compute the magnitude of the induced electromagnetic current as a function of magnetic field, chirality, temperature, and baryon chemical potential.
The axial anomaly plays a crucial role in generating the current, while the electromagnetic anomaly contributes to the current density. The current is found to be proportional to the chiral chemical potential \(\mu_5\), which itself depends on the magnetic field, temperature, and chemical potential. The authors derive the current using three different methods: an energy balance argument, solving the Dirac equation, and computing the thermodynamic potential. They also discuss the implications of the CME in heavy-ion collisions, where the induced current can lead to charge asymmetries. The results show that the current is independent of mass and density, and it is quantized due to the quantization of Landau levels. The CME has potential experimental signatures, such as charge separation along the magnetic field direction, which could provide direct evidence for topologically non-trivial gluon configurations and event-by-event CP violation.The Chiral Magnetic Effect (CME) is a phenomenon where an electromagnetic current is generated along an external magnetic field in a quark-gluon plasma due to the axial anomaly. This effect arises from topological charge-changing transitions, which induce chirality in the plasma. The authors introduce a chiral chemical potential, denoted as \(\mu_5\), to mimic these transitions and study the equilibrium response of the plasma to an applied magnetic field. They compute the magnitude of the induced electromagnetic current as a function of magnetic field, chirality, temperature, and baryon chemical potential.
The axial anomaly plays a crucial role in generating the current, while the electromagnetic anomaly contributes to the current density. The current is found to be proportional to the chiral chemical potential \(\mu_5\), which itself depends on the magnetic field, temperature, and chemical potential. The authors derive the current using three different methods: an energy balance argument, solving the Dirac equation, and computing the thermodynamic potential. They also discuss the implications of the CME in heavy-ion collisions, where the induced current can lead to charge asymmetries. The results show that the current is independent of mass and density, and it is quantized due to the quantization of Landau levels. The CME has potential experimental signatures, such as charge separation along the magnetic field direction, which could provide direct evidence for topologically non-trivial gluon configurations and event-by-event CP violation.