D-instanton derivation of multi-fermion F-terms in supersymmetric QCD

Abstract

We investigate effects of field theory instantons by considering D-instantons in a suitable D3-brane background. In supersymmetric QCD with SU(N-c) gauge group and N-f = N-c flavors, the moduli space of vacua is deformed by instantons. This effect can be described by the chiral interactions which are called multi-fermion F-terms. We derive these chiral interaction terms as D-instanton effects in the presence of D3-branes. For SU(2), the obtained result agrees with the previous result worked out by Beasley and Witten [1]. We also explicitly work out those for the case of the symplectic gauge group, and show that they describe the deformation of the moduli space.