Recently, the laser experiments BMV and GammeV, searching for light shining through walls, have published data and calculated new limits on the allowed masses and couplings for axion-like particles. In this note we point out that these experiments can serve to constrain a much wider variety of hidden-sector particles such as, e.g., minicharged particles and hidden-sector photons. The new experiments improve the existing bounds from the older BFRT experiment by a factor of two. Moreover, we use the new PVLAS constraints on a possible rotation and ellipticity of light after it has passed through a strong magnetic field to constrain pure minicharged particle models. For masses <~0.05 eV, the charge is now restricted to be less than (3-4)x10^(-7) times the electron electric charge. This is the best laboratory bound and comparable to bounds inferred from the energy spectrum of the cosmic microwave background.
@article{arxiv.0711.4991,
title = {Laser experiments explore the hidden sector},
author = {M. Ahlers and H. Gies and J. Jaeckel and J. Redondo and A. Ringwald},
journal= {arXiv preprint arXiv:0711.4991},
year = {2008}
}