Direct Searches for Hidden-Photon Dark Matter with the SHUKET Experiment
  Hidden photons are dark matter candidates motivated by theories beyond the
standard model of particle physics. They mix with conventional photons, and
they can be detected through the very weak electromagnetic radiation they
induce at the interface between a metal and the air. SHUKET (SearcH for U(1)
darK matter with an Electromagnetic Telescope) is a dedicated experiment
sensitive to the hidden photon-induced signal. The results from a hidden photon
search campaign are reported, with no significant detection of a dark matter
signal. Exclusion limits are derived from the observed noise fluctuations in a
5 GHz to 6.8 GHz frequency range, corresponding to a hidden photon mass region
ranging from 20.8 micro-eV to 28.3 micro-eV. SHUKET is currently the most
sensitive instrument in this mass range and the obtained limits on the kinetic
mixing term constrain significantly dark matter models inspired from string
theory.
