Multi-instanton calculus in N=2 supersymmetric QCD

TL;DR

This paper constructs multi-instanton solutions in N=2 SU(2) supersymmetric QCD and compares explicit instanton calculations with exact results, confirming agreement for some cases but revealing discrepancies for others.

Contribution

It provides the first explicit multi-instanton calculations in N=2 supersymmetric QCD and tests the exact results against these calculations.

Findings

Agreement with exact results for N_f=1,2

Discrepancy observed for N_f=3

Explicit two-instanton contribution calculated

Abstract

Microscopic tests of the exact results are performed in N=2 SU(2) supersymmetric QCD. We construct the multi-instanton solution in N=2 supersymmetric QCD and calculate the two-instanton contribution ${\cal F}_2$ to the prepotential ${\cal F}$ explicitly. For $N_f=1,2$, instanton calculus agrees with the prediction of the exact results, however, for $N_f=3$, we find a discrepancy between them.