GammeV Experiment T-969
A gamma to milli-eV particle search

[Photon]-[axion-like particle] regeneration experiment using a "light shining through a wall" technique

[Photon]-[dilaton-like chameleon particle] regeneration using a "particle trapped in a jar" technique

  • Physics motivation for a milli-eV particle (links)
    • Energy frontier (Electroweak-Planck see-saw and string theory)
    • Neutrinos (Mass differences)
    • Astroparticle mysteries (Dark Matter and Dark Energy)
  • Current experimental results (links)
    • Previous experiment BFRT (null result, but milli-eV not excluded)
    • PVLAS (anomalous result using polarization rotations and ellipticities, now maybe not?)
    • CAST (null result looking at the shining sun), BMV (null pseudoscalar result)
    • Theories exist that are consistent with PVLAS's anomalous and CAST's null results
  • The GammeV Experiment (links)
    • Tevatron dipole magnet at 5T
    • Nd:YAG laser at 532nm, 5ns wide pulses, power 160mJ, rep rate 20Hz
    • PMT with single photon sensitivity, 40% QE, 5mm photocathode
    • Data acquisition system uses QuarkNet PMT timing boards
    • An analysis based upon time correlated single photon counting
    • The "wall" is a concave mirror mounted on a movable plunger
    • The "jar" is between our optical windows from which a chameleon afterglow can shine
    • Axion-like particle results PRL, preliminary results arXiv, see also our results page.
    • Chameleon results, PRL, preliminary results arXiv, see our chameleon page.