Electron mass anomalous dimension at O(1/N2tf) in quantum electrodynamics

Abstract

The critical exponent corresponding to the renormalization of the composite operator ψψ is computed in quantum electrodynamics at O(1/N2ƒ) in arbitrary dimensions and covariant gauge at the non-trivial zero of the electron mass which is a the large Nƒ expansion and the exponent corresponding to the anomalous dimensions of the electron mass which is a gauge independent object is deduced. Expanding in powers of ϵ=2−d2 we check it is consistent with the known three loop perturbative structure and determine the subsequent coefficients in the coupling constant expansion to all orders in MS.