Orientifolds with branes at angles

TL;DR

This paper constructs four-dimensional orientifold models with intersecting D6-branes at angles, breaking supersymmetry and producing chiral fermions while ensuring anomaly cancellation.

Contribution

It introduces a new class of supersymmetry-breaking orientifold models with intersecting branes at angles that yield chiral fermions and anomaly-free gauge groups.

Findings

Models contain chiral fermions.

No non-abelian gauge anomalies.

U(1) factors are anomaly-free.

Abstract

We present supersymmetry breaking four dimensional orientifolds of type IIA strings. The compact space is a torus times a four dimensional orbifold. The orientifold group reflects one direction in each torus. RR tadpoles are cancelled by D6-branes intersecting at angles in the torus and in the orbifold. The angles are chosen such that supersymmetry is broken. The resulting four dimensional theories contain chiral fermions. The tadpole cancellation conditions imply that there are no non-abelian gauge anomalies. The models also contain anomaly-free U(1) factors.