Self-interacting fields - key feature of the Standard Model of physics: Exhibition LEPFest 2000

The messengers of the weak interaction -W and Z particles -were discovered at CERN in 1983.After this breakthrough, LEP mass produced W and Z particles so physicists could study them and make careful measurements.These preci- sion studies have shown that W and Z particles behave very differently to photons,messengers of the electromagnetic interaction.Once emitted by an electrically charged particle, a photon has to terminate its mission at another electrically charged particle.Photons do not mingle with each other.W and Z particles,on the other hand,do.The LEP experiments were the first to see this intermingling of messenger particles.