One-instanton calculations in N=2 SU(Nc) Supersymmetric QCD

TL;DR

This paper investigates one-instanton effects in N=2 SU(Nc) supersymmetric QCD, comparing microscopic calculations with exact solutions, revealing agreements and discrepancies depending on the number of flavors.

Contribution

It provides the first detailed comparison of microscopic and exact one-instanton corrections in N=2 SU(Nc) SQCD for various flavor numbers.

Findings

Microscopic and exact calculations agree for most cases.

Discrepancies occur for Nf=2Nc-2 and 2Nc cases.

Differences may stem from ambiguities in the theoretical frameworks.

Abstract

We study the low-energy effective theory in N=2 SU(Nc) supersymmetric QCD with Nf =< 2Nc fundamental hypermultiplets in the Coulomb branch by microscopic and exact approaches. We calculate the one-instanton correction to the modulus u=< 1/2 Tr A^2 > from microscopic instanton calculation. We also study the one-instanton corrections from the exact solutions for Nc=3 with massless hypermultiplets. They agree with each other except for Nf=2Nc-2 and 2Nc cases. These differences come from possible ambiguities in the constructions of the exact solutions or the definitions of the operators in the microscopic theories.