title: Photon regeneration from pseudoscalars at X-ray laser facilities.
abstract: Recently, the PVLAS Collaboration reported an anomalously large rotation of the polarization of light in the presence of a magnetic field in vacuum. As a possible explanation, they consider the existence of a light spin-zero particle coupled to two photons. We propose here a method of independently testing this result 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. With such an experiment the region of parameter space implied by PVLAS could be probed in a matter of minutes.
authors.affiliation: Institute for Advanced Study, Einstein Drive, Princeton, New Jersey 08540, USA.
authors.forename: Raúl
authors.initials: R
authors.lastname: Rabadán
authors.forename: Andreas
authors.initials: A
authors.lastname: Ringwald
authors.forename: Kris
authors.initials: K
authors.lastname: Sigurdson