The higher derivative regularization and quantum corrections in [formula omitted] supersymmetric theories

Abstract

We construct a new version of the higher covariant derivative regularization for a general N=2 supersymmetric gauge theory formulated in terms of N=1 superfields. This regularization preserves both supersymmetries of the classical action, namely, the invariance under the manifest N=1 supersymmetry and under the second hidden on-shell supersymmetry. The regularizing N=2 supersymmetric higher derivative term is found in the explicit form in terms of N=1 superfields. Thus, N=2 supersymmetry is broken only by the gauge fixing procedure. Then we analyze the exact NSVZ β-function and prove that in the considered model its higher loop structure is determined by the anomalous dimension of the chiral superfield Φ in the adjoint representation which is the N=2 superpartner of the gauge superfield V. Using the background field method we find that this anomalous dimension is related with the anomalous dimension of the hypermultiplet and vanishes if the effective action is invariant under N=2 background supersymmetry. As a consequence, in this case the higher loop contributions to β-function also vanish. The one-loop renormalization structure in the considered regularization is also studied by the explicit calculations of the one-loop renormalization constants.