ATTENTION : jour inhabituel / unusual day

We give a short sketch of an argument which helps to reduce the loop order in the perturbative calculation of some anomalous dimensions in N=4 SYM. The approach addresses scalar superfields at the unitarity threshold. Under on-shell supersymmetry, such multiplets exhibit a generalised Konishi anomaly. The one-loop anomaly entirely determines the two-loop anomalous dimension; likewise, higher order corrections to the anomaly influence the higher anomalous dimensions.
The Konishi anomaly is in fact not protected in the scheme of supersymmetric dimensional reduction. We determine the relevant Z-factors consistent with conformal symmetry. The two-loop Z-factor of the anomaly turns out to be singular, and thus the question of one-loop exactness of the anomaly is out of context.

Max-Planck-Institut für Gravitationsphysik, Golm