Branes and instantons intersecting at angles

Understand

We study in detail the system of D6 branes and euclidean D2-brane instantons intersecting at angles in type IIA string theory.

• We find that in the absence of orientifolds the system does not contribute to the low energy superpotential, in agreement with expectations based on effective field theory arguments.
• We also comment on the implications of our results for dual string theory pictures.