Recently, the PVLAS collaboration has reported an anomalously large rotation of the polarization of light in the presence of a magnetic field. As a possible explanation they consider the existence of a light pseudoscalar particle coupled to two photons. In this note, we propose a method of independently testing this result by using a high-energy photon regeneration experiment (the X-ray analogue of "invisible light shining through walls") using the synchrotron X-rays from a free-electron laser (FEL). With such an experiment the region of parameter space implied by PVLAS could be probed in a matter of minutes.
@article{arxiv.hep-ph/0511103,
title = {Photon Regeneration from Pseudoscalars at X-ray Laser Facilities},
author = {Raul Rabadan and Andreas Ringwald and Kris Sigurdson},
journal= {arXiv preprint arXiv:hep-ph/0511103},
year = {2007}
}