Dynamical supersymmetry breaking from unoriented D-brane instantons

We study the local dynamics of an unoriented Z(5)-quiver theory of GUT kind with gauge group U(5) and chiral matter. At strong coupling the non-perturbative dynamics is described in terms of baryon and meson variables satisfying a quantum deformed constraint. We compute the effective superpotential of the theory and show that it admits a line of supersymmetric vacua for vanishing FI terms and a phase where supersymmetry is dynamically broken via gaugino condensation for a non-vanishing FI term