Two-Loop Anomalous Dimension of $N=1$ Supersymmetric Quantum Electrodynamics Regularized Using Higher Covariant Derivatives

We calculate the two-loop anomalous dimension in the $N=1$ supersymmetric electrodynamics regularized through the higher covariant derivative method using the minimum subtraction scheme and show that the result is independent of the form of the regularizing term but does depend on the ratio between the masses $M$ of the Pauli–Villars fields and the dimensional constant $\Lambda$ in the regularizing term. We propose a simple subtraction scheme in which the result is independent of the parameters of the regularization used.