D3/D7 Branes at Singularities: Constraints from Global Embedding and Moduli Stabilisation

TL;DR

This paper develops a method for globally embedding string models with D3/D7 branes at singularities, stabilizing moduli, and achieving phenomenologically viable features like gauge unification and supersymmetry breaking.

Contribution

It provides a concrete construction of globally consistent models with fractional D3-branes and D7-branes at del Pezzo singularities, including moduli stabilization and realistic phenomenology.

Findings

Achieved a controlled de Sitter minimum with stabilized moduli.

Built an explicit example with three chiral matter families and gauge unification.

Linked TeV-scale soft terms to gauge coupling and unification scale values.

Abstract

In the framework of type IIB string compactifications on Calabi-Yau orientifolds we describe how to construct consistent global embeddings of models with fractional D3-branes and connected `flavour' D7-branes at del Pezzo singularities with moduli stabilisation. Our results are applied to build an explicit compact example with a left-right symmetric model at a dP_0 singularity which features three families of chiral matter and gauge coupling unification at the intermediate scale. We show how to stabilise the moduli obtaining a controlled de Sitter minimum and spontaneous supersymmetry breaking. We find an interesting non-trivial dynamical relation between the requirement of TeV-scale soft terms and the correct phenomenological values of the unified gauge coupling and unification scale.