The Nobel Prize in Physics 1992

The multiwire chamber in action

The particle		W and Z

At the same time as Burton Richter discovered the (psi) particle, Samuel C.C. Ting, USA discovered the particle. They were shown to be the same particle, now called the particle. For this discovery Richter and Ting received the Nobel Prize in Physics 1976. The observed mass of the particle of 3.1 GeV corresponds to the mass of slightly more than three protons. The necessary precision was obtained thanks to the proportional chamber.		The discovery of the W and the Z particles was rewarded with the Nobel Prize in Physics in 1984 (Carlo Rubbia and Simon van der Meer, CERN). The particle collision in which the Z particle is created and then rapidly decays into an electron and its antiparticle, the positron, can be seen in the middle of the picture. The tracks of all the charged particles are detected in the central drift chamber. The Z particle is only created in one particle collision in a thousand million.

particle		A rat brain

The (epsilon) particle was discovered in 1977 by Leon Lederman and his research group. The 22 proportional chambers played a very important role in the experiment. In the two 'arms' muons, into which the very short-lived particle decays, were detected.		A five-thousandth-of-a-millimetre-thick slice of a rat brain. The colours illustrate the concentration of molecules sensitive to radiation. With Charpak's detectors this picture could be produced in a day compared to three months with traditional methods.

Contents:
Introduction » Observing the interior of matter » The electron avalanche in the detector » Six quarks and six leptons » The multiwire chamber » The multiwire chamber in action » Further reading »
Based on materials from the 1992 Nobel Poster for Physics. Credits and references for the poster »