The hunt for axions
  Many theoretically well-motivated extensions of the Standard Model of
particle physics predict the existence of the axion and further ultralight
axion-like particles. They may constitute the mysterious dark matter in the
universe and solve some puzzles in stellar and high-energy astrophysics. There
are new, relatively small experiments around the globe, which started to hunt
for these elusive particles and complement the accelerator based search for
physics beyond the Standard Model.
