Energy becomes matter

When high energy particles collide, energy is converted into matter in accordance with Einstein's equation which relates energy to mass, E=mc²

At LEP Z particles are made when electrons and positrons collide with a total head-on energy of 91.2 GeV.

LEP is presently running at a collision energy of 183 GeV. At this energy a pair of W particles can be produced.

The Z and the W particles play an important role as mediators of the weak force which act at very short distances.

Display of a reconstruced event from DELPHI.