Riemann $ζ(3)$- terms in perturbative QED series, conformal symmetry and the analogies with structures of multiloop effects in N=4 supersymmetric Yang-Mills theory

Abstract

As was discovered recently, 5-loop perturbative quenched QED approximation to the QED $β$-function consist from the rational term and the term proportional to $ζ(3)$-function. It is stressed, that this feature is also manifesting itself in the conformal invariant pqQED series for the 4-loop approximation to the anomalous mass dimension. The 4-loop pqQED expression for the singlet contribution into the Ellis-Jaffe polarized sum rule is obtained. It coincides with the similar approximation for the non-singlet coefficient function of Ellis-Jaffe sum rule and of Bjorken polarized sum rule. It is stressed that this property is valid in all orders of perturbation theory thanks to the conformal symmetry of pqQED series and to Crewther relation, which relates non-singlet and singlet coefficient functions of Ellis-Jaffe sum rule with the coefficient functions of non-singlet and singlet Adler D-functions. The basic steps of derivation of Crewther relation in the singlet channel from the AVV triangle diagram are outlined. The similarities between analytical structure of asymptotic series for the coefficient functions in pqQED and for the anomalous dimensions in N=4 conformal invariant supersymmetric Yang-Mills theory are observed. The guess is proposed that the appearance of $ζ(3)$-terms in the pqQED expressions and the absence of $ζ(5)$-terms at the same level is the indication of absence of "wrapping" interactions in pqQED.