Effects of heavy bosonic excitations on QED vacuum

TL;DR

This paper investigates how axion-like excitations influence vacuum birefringence in QED, highlighting the potential significance of these effects within current experimental bounds and their dependence on excitation parameters.

Contribution

It analyzes the impact of axion-like particles on vacuum birefringence, providing a parameter range where these effects could be experimentally relevant.

Findings

The contribution depends on the ratio g_A/m_A.

Current bounds suggest effects could vary from negligible to significant.

Potential for new experimental searches within the low energy regime.

Abstract

We discuss the contribution of axion-like excitations (ALE) to the vacuum birrefringence in the limit $m_A \gtrsim \omega$, where $m_A$ is the mass of the excitation and $\omega$ the energy of test photons interacting with an external (intense) magnetic field. The relevance of this term with respect to the QED contribution depends on the ratio $g_A/m_A$ and, from present bounds on the mass and the coupling constant $g_A$, we find that in the present low energy regime, it ranges from $10^{-14}$ to $10^2$ suggesting an interesting alternative to explore.