Kinetic Mixing at Strong Coupling

TL;DR

This paper explores kinetic mixing in strongly coupled U(1) sectors within string-inspired models, using supersymmetry and Seiberg-Witten theory to compute couplings and phenomenological implications.

Contribution

It introduces a method to compute kinetic mixing in strongly coupled sectors with approximate N=2 supersymmetry using Seiberg-Witten theory, extending analysis beyond weak coupling.

Findings

Computed electric and magnetic kinetic mixing terms in strongly coupled sectors.

Calculated scattering cross sections between visible and extra sector states.

Analyzed effects of supersymmetry breaking on kinetic mixing and phenomenology.

Abstract

A common feature of many string-motivated particle physics models is additional strongly coupled U(1)'s. In such sectors, electric and magnetic states have comparable mass, and integrating out modes also charged under U(1) hypercharge generically yields CP preserving electric kinetic mixing and CP violating magnetic kinetic mixing terms. Even though these extra sectors are strongly coupled, we show that in the limit where the extra sector has approximate N = 2 supersymmetry, we can use formal methods from Seiberg-Witten theory to compute these couplings. We also calculate various quantities of phenomenological interest such as the cross section for scattering between visible sector states and heavy extra sector states, as well as the effects of supersymmetry breaking induced from coupling to the MSSM.