Coupling Right- and Left-Handed Photons Differently to Charged Matter

TL;DR

This paper explores a modified electrodynamics theory where right- and left-handed photons couple differently to charges, breaking Lorentz symmetry and predicting new magnetic forces, with existing data constraining the model.

Contribution

It introduces a Lorentz-violating modification of electrodynamics with differential photon helicity coupling and analyzes its experimental constraints.

Findings

Existing data constrains the modification at about 2 x 10^(-3) level.

The theory predicts novel magnetic forces between perpendicular currents.

Photon helicity coupling differences break Lorentz symmetry and locality.

Abstract

We consider a modification of electrodynamics in which right- and left-circularly polarized photons are coupled to charged sources differently. Even though photon helicity is a Lorentz invariant quantity, such a modification breaks Lorentz symmetry, as well as locality. The modified theory includes novel magnetic forces between perpendicular currents. Existing data can be used to constrain the modification at approximately a 2 x 10^(-3) level.