0 a machine for forcing particles (= extremely small pieces of matter) to hit each other at high speed so scientists can study what is produced:
One experiment, the Large Electron Positron (LEP) collider at CERN, recently detected a number of events compatible with a Higgs boson production.
Fifty metres below the fields north-west of Geneva is a tunnel, which for the past 10 years has been home to the large electron positron collider, LEP.