Discrete Abelian gauge symmetries and axions

TL;DR

This paper explores how intersecting D6-brane models naturally incorporate discrete symmetries and axions, linking massive U(1) gauge symmetries to beyond Standard Model physics extensions.

Contribution

It demonstrates the realization of discrete Zn symmetries and Peccei-Quinn axions within D-brane models, providing explicit examples and model constructions.

Findings

Identification of a generation-dependent Z2 symmetry in a Pati-Salam model

Realization of supersymmetric DFSZ axion models in left-right symmetric frameworks

Axions and Standard Model particles can carry non-trivial Z3 charges

Abstract

We combine two popular extensions of beyond the Standard Model physics within the framework of intersecting D6-brane models: discrete Zn symmetries and Peccei-Quinn axions. The underlying natural connection between both extensions is formed by the presence of massive U(1) gauge symmetries in D-brane model building. Global intersecting D6-brane models on toroidal orbifolds of the type T6/Z2N and T6/Z2xZ2M with discrete torsion offer excellent playgrounds for realizing these extensions. A generation-dependent Z2 symmetry is identified in a global Pati-Salam model, while global left-right symmetric models give rise to supersymmetric realizations of the DFSZ axion model. In one class of the latter models, the axion as well as Standard Model particles carry a non-trivial Z3 charge.