Chiral Symmetry from Type IIA Branes

TL;DR

This paper introduces a string theory construction using branes to realize four-dimensional N=1 supersymmetric gauge theories with chiral matter, revealing a phase transition influenced by the cosmological constant and brane dynamics.

Contribution

It presents a novel brane configuration mechanism in type IIA string theory to model chiral gauge theories and explores a unique phase transition related to brane crossings and cosmological constant effects.

Findings

Constructed N=1 supersymmetric gauge theories with chiral matter using brane setups.

Discovered a phase transition where the number of flavors depends on the cosmological constant.

Demonstrated anomaly cancellation via RR charge conservation in the brane configuration.

Abstract

We propose a mechanism in which, using an eightbrane, a sixbrane ends on a NS brane in type IIA superstring theory. We use this mechanism to construct N=1 supersymmetric gauge theories in four dimensions with chiral matter localized in different points in space. Anomaly cancellation for the gauge theories is satisfied by requiring RR charge conservation for the various type IIA fields. The construction allows us to study a curious phase transition in which the number of flavors in supersymmetric QCD depends on the value of the ten dimensional cosmological constant. These phenomena are related to the fact that every time a D8-brane crosses a NS brane, a D6-brane is created in between them.