New Instanton Effects In Supersymmetric QCD

TL;DR

This paper explores the role of instantons in supersymmetric QCD with N_f>N_c, revealing they generate complex chiral operators and deform the moduli space, extending understanding beyond known cases.

Contribution

It introduces a new understanding of instanton effects for N_f>N_c, showing they produce subtle chiral operators and deform the moduli space structure.

Findings

Instantons generate complex chiral operators for N_f>N_c.

Instantons deform the moduli space of vacua.

The analysis recovers known results for N_f=N_c and N_f=N_c-1 by integrating out flavors.

Abstract

In supersymmetric QCD with SU(N_c) gauge group and N_f flavors, it is known that instantons generate a superpotential if N_f=N_c-1 and deform the moduli space of vacua if N_f=N_c. But the role of instantons has been unclear for N_f>N_c. In this paper, we demonstrate that for N_f>N_c, on the moduli space of vacua, instantons generate a more subtle chiral operator containing (for example) non-derivative interactions of 2(N_f-N_c)+4 fermions. Upon giving masses to some flavors, one can integrate out some fermions and recover the standard results for N_f=N_c and N_f=N_c-1. For N_f=N_c, our analysis gives, in a sense, a more systematic way to demonstrate that instantons deform the complex structure of the moduli space of vacua.