Blumenhagen, RalphCvetič, MirjamLüst, DieterRichter, RobertWeigand, Timo2023-05-232023-05-232008-02-152011-01-25https://repository.upenn.edu/handle/20.500.14332/42788Nonperturbative D-brane instantons can generate perturbatively absent though phenomenologically relevant couplings for type II orientifold compactifications with D-branes. We discuss the generation of the perturbatively vanishing SU(5) GUT Yukawa coupling of type (10 10 5H). Moreover, for a simple globally consistent intersecting D6-brane model, we discuss the generation of mass terms for matter fields. This can serve as a mechanism for decoupling exotic matter.Physical Sciences and MathematicsPhysicsArticle