Testing Chameleon Theories with Light Propagating through a Magnetic Field

TL;DR

This paper investigates how chameleon theories affect light passing through a magnetic field, predicting distinctive vacuum birefringence and dichroism behaviors that differ from axion-like particles, with implications for PVLAS experiments.

Contribution

It provides novel predictions for vacuum birefringence and dichroism induced by chameleon particles, highlighting their unique confinement within experimental setups compared to ALPs.

Findings

Chameleon particles cause greater birefringence than dichroism in experiments.

Chameleon particles are confined within the experimental setup, unlike ALPs.

Predictions differ significantly from standard axion-like particle models.

Abstract

It was recently argued that the observed PVLAS anomaly can be explained by chameleon field theories in which large deviations from Newton's law can be avoided. Here we present the predictions for the dichroism and the birefringence induced in the vacuum by a magnetic field in these models. We show that chameleon particles behave very differently from standard axion-like particles (ALPs). We find that, unlike ALPs, the chameleon particles are confined within the experimental set-up. As a consequence, the birefringence is always bigger than the dichroism in PVLAS-type experiments.