a Department of Physics, Faculty of Science, Chiba University, Chiba 263, Japan
b Graduate School of Science and Technology, Chiba University, Chiba 263, Japan
Abstract:
In the normal phase (where no dynamical fermion mass generation occurs) of the D-dimensional quantum electrodynamics with Nf flavors of fermions, we derive an integral equation which should be satisfied by (the inverse of) the wave function renormalization of the fermion in the Landau gauge. For this we use the inverse Landau-Khalatnikov transformation connecting the nonlocal gauge with the Landau gauge. This leads to a similar equation for the running flavor number in the framework of the 1/Nf resumed Schwinger-Dyson equation. Solving the equation analytically and numerically, we study the infrared behavior and the critical exponent of the 3-dimensional QED (QED3). This confirms that the flavor number in QED3 runs according to the β function which is consistent with the asymptotic freedom as that in 4-dimensional QCD.