Superspace approach to anomalous dimensions in N=4 SYM

In a N = 1 superspace setup and using dimensional regularization, we give a general and simple prescription to compute anomalous dimensions of composi te operators in N = 4, SU(N) supersymmetric Yang-Mills theory, perturbative ly in the coupling constant g. We show in general that anomalous dimensions are responsible for the appearance of higher order poles in the perturbati ve expansion of the two-point function and that their lowest contribution c an be read directly from the coefficient of the 1/epsilon (2) pole. As a ch eck of our procedure we rederive the anomalous dimension of the Konishi sup erfield at order g(2). We then apply this procedure to the case of the doub le trace, dimension 4, superfield in the 20 of SU(4) recently considered in the literature. We find that its anomalous dimension vanishes for all N in agreement with previous results. (C) 2001 Elsevier Science B.V. All rights reserved.