Dafne

DAFNE or DAΦNE, is an electron-positron collider at the INFN Frascati National Laboratory in Frascati, Italy. It consists of 2 accelerator rings, both approximately 100 meters in length. Since 1999 it has been colliding electrons and positrons at a center of mass energy of 1.02 GeV to create phi mesons (φ). 85% of these decay into kaons (K), whose physics is the subject of most of the experiments... (Wikipedia)