Intersecting Brane Worlds -- A Path to the Standard Model ?

TL;DR

This review explores the geometrical framework of intersecting D6-branes in type IIA string theory, detailing how they can realize the Standard Model, analyze their effective actions, and address issues like supersymmetry and proton decay.

Contribution

It provides a comprehensive overview of intersecting brane models, including their construction, effective actions, and phenomenological implications, with specific calculations on scalar potentials and gauge couplings.

Findings

Construction of chiral spectra from intersecting branes

Calculation of scalar potentials and gauge threshold corrections

Insights into proton decay mechanisms

Abstract

In this review we describe the general geometrical framework of brane world constructions in orientifolds of type IIA string theory with D6-branes wrapping 3-cycles in a Calabi-Yau 3-fold. These branes generically intersect in points on the internal space, and the patterns of intersections govern the chiral fermion spectra. We discuss how the open string spectra in intersecting brane models are constructed, how the Standard Model can be embedded, and also how supersymmetry can be realized in this class of string vacua. After the general considerations we specialize the discussion to the case of orbifold backgrounds with intersecting D6-branes and to the quintic Calabi-Yau manifold. Then, we discuss parts of the effective action of intersecting brane world models. Specifically we compute from the Born-Infeld action of the wrapped D-branes the tree-level, D-term scalar potential, which is important for the stability of the considered backgrounds as well as for questions related to supersymmetry breaking. Second, we review the recent computation concerning of gauge coupling unification and also of one-loop gauge threshold corrections in intersecting brane world models. Finally we also discuss some aspects of proton decay in intersecting brane world models.