No Net Charge Separation in Hot QCD in a Magnetic Field

We study the realization of axion electrodynamics in QCD in the presence of a background magnetic field at temperatures high enough for the occurrence of topological charge transitions that are reflected in the presence of a $\theta$-vacuum term in the action. We show that in this system, the Maxwell equations contain two equal and opposite electric currents that are proportional to the time derivative of the axion field $\theta$. One of these currents comes directly from the Abelian chiral anomaly term in the action and can be interpreted as a polarization current due to the magnetoelectricity of the system with CP-broken symmetry. The other current is obtained from the regular tadpole diagrams and can be understood as produced by the medium chiral imbalance and the single spin projection of the quarks in the lowest Landau level. Since the two currents cancel out, the net electric charge separation along the magnetic field, a phenomenon known as the Chiral Magnetic Effect, does not take place in hight-T QCD at least in equilibrium, in sharp contrast with many claims in the literature. We discuss the similarities and differences with Weyl semimetals in a magnetic field.Comment: 17 page

Magnetic Response in Anyon Fluid at High Temperature

The magnetic response of the charged anyon fluid at temperatures lower and larger than the fermion enery gap $\omega_{c}$ is investigated in the self-consistent field approximation. We prove that the anyon system with boundaries exhibits a total Meissner effect at temperatures smaller than the fermion energy gap ($T\ll \omega_{c}$). The London penetration length at $T$ $\sim 200K$ is of the order $\lambda \sim 10^{-5}cm$. At $T\gg \omega_{c}$ a new phase, characterized by an inhomogeneous magnetic penetration, is found. We conclude that the energy gap, $\omega_{c},$ defines a scale that separates two phases: a superconducting phase at $T\ll \omega_{c}$, and a non-superconducting one at $T\gg \omega_{c}$.Comment: 7 pages, Talk presented at SILAFAE'98. April 8-11, 1998, San Juan, Puerto Ric

Effects of Bose-Einstein Condensation on forces among bodies sitting in a boson heat bath

We explore the consequences of Bose-Einstein condensation on two-scalar-exchange mediated forces among bodies that sit in a boson gas. We find that below the condensation temperature the range of the forces becomes infinite while it is finite at temperatures above condensation.Comment: 10 pages, 2 figure

Dynamically Induced Zeeman Effect in Massless QED

It is shown that in non-perturbative massless QED an anomalous magnetic moment is dynamically induced by an applied magnetic field. The induced magnetic moment produces a Zeeman splitting for electrons in Landau levels higher than $l=0$. The expressions for the non-perturbative Lande g-factor and Bohr magneton are obtained. Possible applications of this effect are outlined.Comment: Extensively revised version with several misprints and formulas corrected. In this new version we included the non-perturbative Lande g-factor and Bohr magneto