Covariant Harmonic Supergraphity for N = 2 Super Yang--Mills Theories

TL;DR

This paper reviews the background field method in N=2 harmonic superspace, applying covariant supergraph techniques to prove non-renormalization theorems and compute low-energy effective actions in N=2 and N=4 super Yang-Mills theories.

Contribution

It introduces a covariant harmonic supergraph approach to rigorously establish non-renormalization theorems and calculate low-energy actions in N=2 supersymmetric gauge theories.

Findings

Proved N=2 non-renormalization theorem.

Computed holomorphic low-energy action for N=2 SU(2) super Yang-Mills.

Calculated leading non-holomorphic correction for N=4 SU(2) super Yang-Mills.

Abstract

We review the background field method for general N = 2 super Yang-Mills theories formulated in the N = 2 harmonic superspace. The covariant harmonic supergraph technique is then applied to rigorously prove the N=2 non-renormalization theorem as well as to compute the holomorphic low-energy action for the N = 2 SU(2) pure super Yang-Mills theory and the leading non-holomorphic low-energy correction for N = 4 SU(2) super Yang-Mills theory.