Kinetic Mixing of U(1)s in Heterotic Orbifolds

TL;DR

This paper investigates kinetic mixing between U(1) gauge symmetries in heterotic orbifolds, providing a simple formula for mixing in certain models and exploring phenomenological implications such as hidden photons.

Contribution

It introduces a new method to analyze kinetic mixing in heterotic orbifolds and applies it to specific models, revealing non-trivial mixing possibilities.

Findings

Non-vanishing kinetic mixing in Z_6-II orbifolds without Wilson lines

Existence of supersymmetric vacua with hypercharge mixing in Mini-Landscape models

Potential for hidden photons in heterotic orbifold compactifications

Abstract

We study kinetic mixing between massless U(1) gauge symmetries in the bosonic formulation of heterotic orbifold compactifications. For non-prime Z_N factorisable orbifolds, we find a simple expression of the mixing in terms of the properties of the N=2 subsectors, which helps understand under what conditions mixing can occur. With this tool, we analyse Z_6-II heterotic orbifolds and find non-vanishing mixing even without including Wilson lines. We show that some semi-realistic models of the Mini-Landscape admit supersymmetric vacua with mixing between the hypercharge and an additional U(1), which can be broken at low energies. We finally discuss some phenomenologically appealing possibilities that hidden photons in heterotic orbifolds allow.