Brane Dynamics and Chiral non-Chiral Transitions

TL;DR

Brane Dynamics and Chiral non-Chiral Transitions analyzes Type IIA brane configurations that realize four-dimensional N=1 gauge theories with localized chiral matter. It derives cross/fork configurations producing chiral multiplets and superpotentials, extends to orientifold-projected product groups yielding chiral theories with adjoints and two-index tensors, and investigates their flat directions and non-Abelian dualities. A key insight is the occurrence of small instanton transitions that interpolate between chiral and non-chiral spectra, tying four-dimensional chirality changes to six-dimensional instanton dynamics. The work provides a cohesive geometric framework for dualities, moduli spaces, and phase transitions in N=1 gauge theories, including generalizations to multiple NS branes and various orientifold charges.

Abstract

We study brane realizations of chiral matter in N=1 supersymmetric gauge theories in four dimensions. A "cross" configuration which leads to "flavor doubling" is found to have a superpotential. The main example is realized using a special "fork" configuration. Many of the results are found by studying a SU times SU product gauge group first. The chiral theory is then an orientifold projection of the product gauge group. An interesting observation in the brane picture is that there are transitions between chiral and non chiral models. These transitions are closely related to small instanton transitions in six dimensions.