Chiral D-brane Models with Frozen Open String Moduli

TL;DR

This paper constructs chiral D-brane models on a specific orientifold that eliminate unwanted adjoint fields, enabling the realization of asymptotically free gauge theories and flux vacua.

Contribution

It introduces a method to build N=1 chiral D-brane models with frozen open string moduli, avoiding extra adjoint fields and enabling new flux compactifications.

Findings

Constructed a Pati-Salam-like model with asymptotically free SU(4) gauge group.

Derived consistency conditions for rigid 3-cycle wrapped D-branes.

Embedded models into flux compactification framework, creating new chiral flux vacua.

Abstract

Most intersecting D-brane vacua in the literature contain additional massless adjoint fields in their low energy spectrum. The existence of these additional fields make it difficult to obtain negative beta functions and, eventually, asymptotic freedom. We address this important issue for N=1 intersecting D-brane models, rephrasing the problems in terms of (open string) moduli stabilization. In particular, we consider a Z2 x Z2 orientifold construction where D6-branes wrap rigid 3-cycles and such extra adjoint fields do not arise. We derive the model building rules and consistency conditions for intersecting branes in this background, and provide N=1 chiral vacua free of adjoint fields. More precisely, we construct a Pati-Salam-like model whose SU(4) gauge group is asymptotically free. We also comment on the application of these results for obtaining gaugino condensation in chiral D-brane models. Finally, we embed our constructions in the framework of flux compactification, and construct new classes of N=1 and N=0 chiral flux vacua.