N=2 gauge theories on systems of fractional D3/D7-branes

We study a bound state of fractional D3/D7-branes in the ten-dimensional space R-1.5 x R-4/Z(2) using the boundary state formalism. We construct the boundary actions for this system and show that higher-order terms in the twisted fields are needed in order to satisfy the zero-force condition. We then find the classical background associated to the bound state and show that the gauge theory living on a probe fractional D3-brane correctly reproduces the perturbative behavior of a four-dimensional N = 2 supersymmetric gauge theory with fundamental matter. (C) 2002 Elsevier Science B.V. All rights reserved.