XMASS is a multipurpose physics experiment in Japan. It is a large cryogenic storage dewar, a tank of liquid xenon equipped with photosensors monitoring flashes of light that might be caused by interactions with hypothetical dark matter particles. Unlike a cryogenic particle detector, it operates at temperatures relatively far from absolute zero (specifically, 165 K (−163 °F)).[1] In addition to searching for dark matter, XMASS is also studying neutrinoless double beta decay and solar neutrinos. The project is conducted by a team at Institute for Cosmic Ray Research, University of Tokyo.[2]
Its results have not confirmed the annual variation seen in some earlier experiments.[3]