On search for eV hidden-sector photons in Super-Kamiokande and CAST experiments

If light hidden sector photons (gamma's) exist, they could be produced through kinetic mixing with solar photons in the eV energy range. We propose to search for this hypothetical gamma'-flux with the Super-Kamiokande and/or upgraded CAST detectors. The proposed experiments are sensitive to the gamma-gamma' mixing strength as small as 10(-5) greater than or similar to chi greater than or similar to 10(-9) for the gamma' mass region 10(-4) less than or similar to m(gamma') less than or similar to 10(-1) eV and, in the case of non-observation, would improve limits recently obtained from photon regeneration laser experiments for this mass region. (c) 2008 Elsevier B.V. All rights reserved.